Occupancy sensing systems and methods
The present disclosure provides systems and methods for improved occupancy sensing. The methods and systems can deploy various signal threshold adjustments and/or signal analysis algorithms in response to sensed signals having a given quality, such as exceeding a threshold. In some cases, signal thresholds are lowered following an initial generated signal exceeding a first, higher threshold. In some cases, time-dependent signals are monitored using algorithms that analyze the signals for variations that are characteristic of human usage. Methods are disclosed for determining if two motion sensors are observing the same or overlapping spaces. Systems and methods for calibrating motion sensing systems are also disclosed.
1. A method of operating a motion sensor system, the motion sensor system including a motion sensor that generates a motion signal in response to a sensed motion in a space to which the motion sensor is associated, the method including:
a) acquiring a baseline signal from the motion sensor when the space is unoccupied;
b) acquiring the motion signal from the motion sensor over a predetermined length of time, thereby providing a time-dependent motion signal;
c) processing the time-dependent motion signal using the base line signal and a human-like motion analysis algorithm that distinguishes between motions having a time-varying component that is characteristic of a human movement pattern, the human movement pattern being selected from a plurality of human movement patterns based on a prior occupancy determination; and
d) in response to the human-like motion analysis algorithm determining that a motion is characteristic of the human movement pattern, providing an occupancy signal indicative of an occupancy of a space to which the motion sensor is associated.
2. The method of claim 1 , wherein the human-like motion analysis algorithm includes a frequency-analysis algorithm.
3. The method of claim 1 , wherein the human-like motion analysis algorithm includes a narrow bandpass filter configured to isolate frequencies that are characteristic of the human movement pattern.
4. The method of claim 3 , wherein the frequencies that are characteristic of the human movement pattern are between 0.1 Hz and 2 Hz.
5. The method of claim 1 , wherein the human-like motion analysis algorithm includes a transform of the time-dependent motion signal into a frequency-domain signal.
6. The method of claim 1 , wherein the human-like motion analysis algorithm includes a derivative of the time-dependent motion signal.
7. The method of claim 1 , wherein the human-like motion analysis algorithm includes an integral of the time-dependent motion signal.
8. The method of claim 1 , wherein the human-like motion analysis algorithm self-adjusts over time to account for feedback regarding previous occupancy determinations.
9. The method of claim 1 , wherein the space is a room or an arbitrarily-defined area or volume.
10. The method of claim 1 , wherein the motion sensor is an infrared sensor.
11. The method of claim 1 , wherein the motion sensor is configured to provide at least 90% coverage of the space.
12. The method of claim 1 , wherein the motion sensor is configured to communicate via a low energy consumption communication protocol or via a wireless communication protocol.
13. The method of claim 1 , wherein the motion sensor is a passive motion sensor.
14. The motion sensor system for executing the method of claim 1 , the motion sensor system including the motion sensor, a processor, and a memory having stored thereon instructions that, when executed by the processor, cause the processor to execute the method.
15. The motion sensor system of claim 14 , the motion sensor system further comprising a gateway configured to send signals to and receive signals from the motion sensor.
16. The motion sensor system of claim 14 , wherein the processor and the memory are co-located with the motion sensor.
17. The method of claim 1 , wherein the plurality of human movement patterns include a human movement pattern characteristic of an entrance into the space.
18. The method of claim 1 , wherein the plurality of human movement patterns includes a movement pattern characteristic of a continued occupancy of the space.
19. The method of claim 1 , wherein the prior occupancy determination includes a determination that the space is unoccupied.
20. The method of claim 1 , wherein determining that the motion is characteristic of the human motion pattern is at least partially based on a size of the space.