Digital occupancy sensor light control

• US 7,924,155 B2
• Filed: 01/07/2008
• Issued: 04/12/2011
• Est. Priority Date: 01/07/2008
• Status: Active Grant

• Current Assignee: Leviton Manufacturing Company Incorporated
• Original Assignee: Leviton Manufacturing Company Incorporated
• Inventors: Lombardi, Al, Soccoli, Paul, Ostrovsky, Michael
• Primary Examiner(s): GOINS, DAVETTA WOODS
• Application Number:
  US11/970,017
• Publication Number:
  US 20090174552A1
• Time in Patent Office: 1,191 Days
• Field of Search: 340/567, 340/565, 340/566, 340/584, 340/573.1, 250/339.02, 250/338.3, 250/342, 250/221, 250/239
• US Class Current: 340/567
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0228 Control of working procedures; Failure detection; Spectral bandwidth calculation
• CPC Class Codes: G01J 1/18 using comparison with a reference electric value
• CPC Class Codes: G01J 5/026 Control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
• CPC Class Codes: G01J 5/34 using capacitors, e.g. pyroelectric capacitors
• CPC Class Codes: H05B 47/13 by using passive infrared detectors
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A method of sensing motion in a predetermined area is provided. The method may include using a digital output motion sensor to produce a digital output signal indicative of the presence of motion in the predetermined area. The method may further include transmitting the digital output signal along a signal path independent of analog amplification and filtering. The method may also include using a microprocessor coupled to the signal path to receive the digital output signal and to process the digital output signal.

Claims

1. A passive infrared-based occupancy sensor load control comprising:

a digital output motion sensor that produces a digital output signal and transmits the digital output signal along a signal path independent of analog amplification and filtering, the output signal that indicates the presence or absence of motion, the output signal including signal information that is free from losses attributable to analog amplification and analog filtering; and

a microprocessor coupled to the signal path, the microprocessor that receives and processes the digital output signal to produce a second signal, the second signal for comparing to a threshold, and controls resetting of a time delay for switching of the load in response to the comparison of the second signal to the threshold.

2. The passive infrared-based occupancy sensor load control of claim 1 wherein the digital output signal comprises signal information that falls outside a predetermined frequency band.

3. The passive infrared-based occupancy sensor load control of claim 2 wherein the predetermined frequency band is between about 1 Hz and about 10 Hz.

4. The passive infrared-based occupancy sensor load control of claim 2 wherein the predetermined frequency band is between about 0.25 Hz and about 15 Hz.

5. The passive infrared-based occupancy sensor load control of claim 1 wherein the microprocessor is configured to implement a sensitivity adjustment using digital signal processing.

6. The passive infrared-based occupancy sensor load control of claim 1 wherein the microprocessor is configured to implement an adapting algorithm that is adapted to adjust the load control in response to the digital output signal.

7. The passive infrared-based occupancy sensor load control of claim 6 wherein the adapting algorithm comprises conditioning the digital output signal and adjusting the load control at least in part in response to analyzing the time constants of the conditioned digital output signal.

8. The passive infrared-based occupancy sensor load control of claim 1 further comprising a relay.

9. The passive infrared-based occupancy sensor load control of claim 1 further comprising a dimmer.

10. The passive infrared-based occupancy sensor load control of claim 1 further comprising a visible indicator of a predetermined load time-out, the visible indicator comprising a load dimming sequences and/or a load brightening sequence.

11. The passive infrared-based occupancy sensor load control of claim 1 further comprising a brightness level display that indicates the duration of a delayed-off time.

12. The passive infrared-based occupancy sensor load control of claim 1 further comprising a brightness level display that indicates a load dim level and/or the duration of a delayed-off time.

13. The passive infrared-based occupancy sensor load control of claim 1, the load control further comprising an LED display, the load control that displays on the LED display a measured level of ambient light.

14. The passive infrared-based occupancy sensor load control of claim 1, the load control further comprising a programming mode implemented on the microprocessor, the programming mode adapted to receive digitally programmed user adjustments.

15. The passive infrared-based occupancy sensor load control of claim 14, wherein the programming mode is entered by pressing and holding a load ON/load OFF button for a predetermined period of time.

16. The passive infrared-based occupancy sensor load control of claim 14, wherein the programming mode is entered by pressing and holding a load ON/load OFF button and a bright button for a predetermined period of time.

17. The passive infrared-based occupancy sensor load control of claim 1 further comprising an automatic-ON setting.

18. The passive infrared-based occupancy sensor load control of claim 1 further comprising a manual-ON setting.

19. The passive infrared-based occupancy sensor load control of claim 1 wherein the load is one of a light, a fan, an HVAC system, and an electronically operable window shade.

20. A method of sensing motion in a predetermined area, the method comprising:

using a digital output motion sensor to produce a digital output signal indicative of the presence of motion in the predetermined area;

transmitting the digital output signal along a signal path independent of analog amplification and filtering;

using a microprocessor coupled to the signal path to receive the digital output signal and to process the digital output signal to produce a second signal, the second signal for comparing to a threshold; and

using the microprocessor to control resetting of a time delay for switching of a load in response to the comparison of the second signal to the threshold, the time delay representing a magnitude of elapsed time since the load changed state.

21. The method of claim 20, the processing the digital output signal further comprising implement a sensitivity adjustment to the digital output signal.

22. The method of claim 20 further comprising using the microprocessor to implement adapting algorithms that to adjust the load control in response to the digital output signal.

23. The method of claim 22 further comprising conditioning the digital output signal and adjusting the load control at least in part in response to analyzing the time constants of the conditioned digital output signal.

24. The method of claim 20 further comprising providing a load dimming sequence and/or a load brightening sequence as an indication of a predetermined load time-out.

25. The method of claim 20 further comprising providing an indication of the duration of a delayed-off time.

26. The method of claim 20 further comprising displaying an indication of a measured load level on an LED display.

27. The method of claim 20 further comprising implementing a programming mode on the microprocessor, the programming mode adapted to receive user adjustments.

28. The method of claim 27 further comprising entering the programming mode by pressing and holding a load ON/load OFF actuator for a predetermined period of time.

29. The method of claim 27 further comprising entering the programming mode by pressing and holding a load ON/load OFF actuator and a bright button for a predetermined period of time.

30. The method of claim 20 further comprising using the microprocessor to place a load in an ON condition in response to detection of motion.

31. The method of claim 20 further comprising using the microprocessor to place a load in an OFF condition in response to detection of no motion for a predetermined period of time.

32. The method of claim 20 further comprising enabling the use of output signal information in the output signal that falls outside a predetermined frequency band.

33. The method of claim 32 wherein the predetermined frequency band is between about 1 Hz and about 10 Hz.

34. The method of claim 32 wherein the predetermined frequency band is between about 0.25 Hz and about 15 Hz.

35. A method for comparing historic information with obtained characteristics of an output signal from a motion sensor in order to adjust the sensitivity and/or the delayed-off time of the sensor, the method comprising:

receiving the output signal from the sensor prior to amplification of the output signal;

filtering the output signal to obtained a filtered signal;

analyzing the time constants of the filtered signal;

calculating an adaptive threshold at least in part based on signal conditions;

comparing the conditioned signal with the adaptive threshold; and

generating a control signal in response to the comparing the conditioned signal with the adaptive threshold.

36. The method of claim 35, the calculating an adaptive threshold at least in part based on signal conditions comprising calculating the adaptive threshold based on at least one of the current state of a predetermined load, a magnitude of elapsed time since the load changed state, and an occupancy signal frequency.