Occupancy sensor with improved functionality

• US 9,671,526 B2
• Filed: 06/23/2014
• Issued: 06/06/2017
• Est. Priority Date: 06/21/2013
• Status: Active Grant

• Current Assignee: Crestron Electronics Incorporated
• Original Assignee: Crestron Electronics Incorporated
• Inventors: Kumar, Russikesh
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US14/311,580
• Publication Number:
  US 20140379305A1
• Time in Patent Office: 1,079 Days
• Field of Search: 702190
• CPC Class Codes: G01V 11/00 Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/12 by detecting audible sound
• CPC Class Codes: H05B 47/13 by using passive infrared detectors
• CPC Class Codes: H05B 47/175 by remote control
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

An occupancy sensor detects the occupancy state of a monitored area. The occupancy sensor may be mounted in a standard junction box at various angles and one or more of the ultrasonic sensors may be disabled. The occupancy sensor includes a PIR sensor and one or more ultrasonic sensors. The sensor sensitivities and timeout settings may be programmed by a technician or user via an IR interface or via a network interface. The settings may be changed according to control system logic or some other factor such as date, time or room conditions. Setup of the sensor may also be performed via the IR interface or network interface. The occupancy outputs both a signal taking into account the timeout period as well as a raw data signal. The IR interface may be used to relay messages between a control system and external devices. Algorithms employed in the occupancy sensor allow for the occupancy sensor to process analog signals from sensors to determine the room state, enhance performance such as by reducing false trips, enhance energy savings and force sensors into vacancy or occupancy mode. The occupancy sensor additionally comprises a microphone. Sound can be required to qualify detection from another sensor and may be employed to prolong the occupancy state once it is established.

Claims

1. An occupancy sensor for determining an occupancy state of a monitored area, the occupancy sensor comprising:

a passive infrared sensor configured for generating a signal based on sensed infrared radiation of the monitored area;

an ultrasonic transducer sensor configured for generating a signal based on sensed ultrasonic echo of the monitored area;

a memory encoding one or more processor-executable instructions; and

a processor configured to load the one or more processor-executable instructions when encoded from the memory wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising;

receiving at least one signal from the passive infrared sensor and the ultrasonic transducer sensor,

sampling the at least one signal at an analog to digital converter to produce at least one sampled signal,

filtering the at least one sampled signal through a digital bandpass filter to produce at least one filtered signal,

comparing the at least one filtered signal to a first sensitivity threshold,

maintaining a count of occupancy detections,

for each filtered signal, increasing the count by a first predefined value if the filtered signal is above the sensitivity threshold and decreasing the count by a second predefined value if the filtered signal is below the sensitivity threshold,

comparing the count to a count threshold, and

determining the monitored area to be occupied if the count is larger than the count threshold.

2. The occupancy sensor of claim 1 wherein:

the at least one signal comprises a first signal received from the passive infrared receiver and a second signal received from the ultrasonic transducer and the first signal corresponds to a first count and the second signal corresponds to a second count; and

the one or more processor executable instructions, when executed by the processor, cause acts to be performed further comprising determining the occupancy state of the monitored area based on a comparison of the first count to the count threshold, a comparison of the second count to the count threshold and a combinational logic operator.

3. The occupancy sensor of claim 2 wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

determining the monitored area to be occupied if the combinational logic operator is an or operator and at least one of the first count and the second count are above the count threshold;

determining the monitored area to be occupied if the combinational logic operator is an and operator and the first count and the second count are above the count threshold.

4. The occupancy sensor of claim 3 further comprising a network interface configured for bidirectional communication on a control network and wherein the combinational logic operator is received from the control network via the network interface.

5. The occupancy sensor of claim 4 wherein the network interface is further configured for receiving at least one of a high frequency cutoff setting and a low frequency cutoff setting.

6. The occupancy sensor of claim 3 further comprising a wireless communication interface configured for bidirectional wireless communication and wherein the combinational logic operator is received from a user via the wireless communication interface.

7. The occupancy sensor of claim 6 further wherein the wireless communication interface is further configured for receiving at least one of a high frequency cutoff setting, a low frequency cutoff setting, the sensitivity threshold, and the count threshold.

8. The occupancy sensor of claim 7 wherein the wireless communication interface is an infrared interface configured for communicating with a wireless remote control.

9. The occupancy sensor of claim 8 further comprising a network interface and wherein:

the infrared interface is further configured for receiving and transmitting RC-5 encoded messages; and

the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising converting an RC-5 encoded message to a network message and converting a network message to an RC-5 encoded message.

10. The occupancy sensor of claim 1 wherein at least one of the sensitivity threshold and the count threshold are dependent on a time event.

11. The occupancy sensor of claim 1 wherein at least one of the sensitivity threshold and the count threshold are dependent of the occupancy state of the monitored area.

12. The occupancy sensor of claim 11 wherein the at least one of the sensitivity threshold and the count threshold is higher when the monitored area is occupied.

13. The occupancy sensor of claim 1 wherein at least one of the sensitivity threshold and the count threshold are dependent on an occupancy state of a second monitored area.

14. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

determining the monitored area to be occupied if the count is equal to the count threshold.

15. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

setting the count to the count threshold if the count is larger than the count threshold.

16. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

for each filtered signal, increasing the count by the first predefined value if the filtered signal is equal to the sensitivity threshold.

17. The occupancy sensor of claim 1, wherein the first predefined value and the second predefined value are equal.

18. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

determining an absolute value of the at least one filtered signal.

19. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

determining the monitored area to be vacant if the count is less than the count threshold.

20. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

determining if the count is larger than zero;

decrementing the count if the count is larger than zero.

21. The occupancy sensor of claim 1, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

determining if the decremented count is less than or equal to zero;

determining the monitored area to be vacated if the decremented count is less than or equal to zero.

22. The occupancy sensor of claim 21, wherein the one or more processor executable instructions, when executed by the processor, cause acts to be performed comprising:

setting the decremented count to zero when the decremented count is less than zero.

23. A method for detecting an occupancy state of a monitored area comprising the steps of:

sampling at least one signal from a passive infrared sensor and an ultrasonic transducer sensor at an analog to digital converter to produce at least one sampled signal;

filtering the at least one sampled signal through a digital bandpass filter to produce at least one filtered signal;

comparing the at least one filtered signal to a sensitivity threshold;

maintaining a count of occupancy detections;

for each of the at least one filtered signals, increasing the count by a first predefined value if the filtered signal is larger than the sensitivity threshold and decreasing the count by a second predefined value if the filtered signal is not larger than the sensitivity threshold; and

comparing the count to a count threshold; and

determining the monitored area to be occupied if the count is larger than the count threshold.

24. The method of claim 23 further comprising the step of determining at least one of the sensitivity threshold and the count threshold according to a time of day, a day of week.

25. The method of claim 23 further comprising the step of determining at least one of the sensitivity threshold and the count threshold according to a day of week.

26. The method of claim 23 further comprising the step of determining at least one of the sensitivity threshold and the count threshold according to the occupancy state of the monitored area.

27. The method of claim 23 further comprising the step of determining at least one of the sensitivity threshold and the count threshold according to the occupancy state of a second monitored area.

28. The method of claim 23 further comprising the step of receiving at least one of the sensitivity threshold and the count threshold from a control network.

29. The method of claim 23 further comprising the step of receiving at least one of a high bandwidth cutoff setting and a low bandwidth cutoff setting from a control network.

30. The method of claim 23 further comprising the step of receiving at least one of the sensitivity threshold and the count threshold from a user remote control device.

31. The method of claim 23 further comprising the step of receiving at least one of a high bandwidth cutoff setting and a low bandwidth cutoff setting from a user remote control device.

32. The method of claim 23 further comprising the steps of:

receiving an RC-5 encoded message via a wireless communication interface;

converting the RC-5 encoded message to a network message; and

transmitting the network message to a control network via a network interface.

33. A method for detecting an occupancy state of a monitored area comprising the steps of:

sampling a first signal from a passive infrared sensor and a second signal from an ultrasonic transducer sensor at an analog to digital converter to produce a first sampled signal and a second sampled signal;

filtering the first sampled signal and the second sampled signal through a digital bandpass filter to produce a first filtered signal and a second filtered signal;

comparing the first filtered signal and the second filtered signal to a sensitivity threshold;

maintaining a first count of occupancy detections by the passive infrared sensor and a second count of occupancy detections by the ultrasonic transducer sensor;

increasing the first count by a first predefined value if the filtered first signal is above the sensitivity threshold and decreasing the first count by a second predefined value if the filtered first signal is below the sensitivity threshold;

increasing the second count by a first predefined value if the filtered second signal is above the sensitivity threshold and decreasing the second count by a second predefined value if the filtered second signal is below the sensitivity threshold;

comparing the first count and the second count to a count threshold;

determining the monitored area to be occupied if at least one of the first count and the second count are larger than the count threshold and the combinational logic operator is an or operator; and

determining the monitored area to be occupied if both the first count and the second count are larger than the count threshold.

34. The method of claim 33 further comprising the step of determining the combinational logic operator according to the occupancy state of the monitored area.

35. The method of claim 33 further comprising the step of receiving the combinational logic operator according to the occupancy state of a second monitored area.