Occupancy Estimation using Ultrasonic Chirps
Anthony Rowe, Oliver Shih

Citation
Anthony Rowe, Oliver Shih. "Occupancy Estimation using Ultrasonic Chirps". ICCPS: ACM/IEEE International Conference on Cyber-Physical Systems, ACM/IEEE, April, 2015.

Abstract
Estimating the number of people within a room is important for a wide variety of applications including: HVAC load management, scheduling room allocations and guiding first responders to areas with trapped people. In this paper, we present an active sensing technique that uses changes in a room's acoustic properties to estimate the number of occupants. Frequency dependent models of reverberation and room capacity are often used when designing auditoriums and concert halls. We leverage this property by using changes in the ultrasonic spectrum reflected back from a wide-band transmitter to estimate occupancy. A centrally located beacon transmits an ultrasonic chirp and then records how the signal dissipates over time. By analyzing the frequency response over the chirp's bandwidth at a few known occupancy levels, we are able to extrapolate the re- sponse as the number of people in the room changes. We explore the design of an excitation signal that best senses the environment with the fewest number of training sam- ples. Through experimentation, we show that our approach is able to capture the number of people in a wide-variety of room configurations with accuracy on average of 90% with as few as two training points. Finally, we provide a simple mechanism that allows our system to recallibrate when we know the room is empty so that it can adapt dynamically over time.

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Citation formats

• HTML

  Anthony Rowe, Oliver Shih. <a
  href="http://www.terraswarm.org/pubs/491.html"
  >Occupancy Estimation using Ultrasonic Chirps</a>,
  ICCPS: ACM/IEEE International Conference on Cyber-Physical
  Systems, ACM/IEEE, April, 2015.

• Plain text

  Anthony Rowe, Oliver Shih. "Occupancy Estimation using
  Ultrasonic Chirps". ICCPS: ACM/IEEE International
  Conference on Cyber-Physical Systems, ACM/IEEE, April, 2015.

• BibTeX

  @inproceedings{RoweShih15_OccupancyEstimationUsingUltrasonicChirps,
      author = {Anthony Rowe and Oliver Shih},
      title = {Occupancy Estimation using Ultrasonic Chirps},
      booktitle = {ICCPS: ACM/IEEE International Conference on
                Cyber-Physical Systems},
      organization = {ACM/IEEE},
      month = {April},
      year = {2015},
      abstract = {Estimating the number of people within a room is
                important for a wide variety of applications
                including: HVAC load management, scheduling room
                allocations and guiding first responders to areas
                with trapped people. In this paper, we present an
                active sensing technique that uses changes in a
                room's acoustic properties to estimate the number
                of occupants. Frequency dependent models of
                reverberation and room capacity are often used
                when designing auditoriums and concert halls. We
                leverage this property by using changes in the
                ultrasonic spectrum reflected back from a
                wide-band transmitter to estimate occupancy. A
                centrally located beacon transmits an ultrasonic
                chirp and then records how the signal dissipates
                over time. By analyzing the frequency response
                over the chirp's bandwidth at a few known
                occupancy levels, we are able to extrapolate the
                re- sponse as the number of people in the room
                changes. We explore the design of an excitation
                signal that best senses the environment with the
                fewest number of training sam- ples. Through
                experimentation, we show that our approach is able
                to capture the number of people in a wide-variety
                of room configurations with accuracy on average of
                90% with as few as two training points. Finally,
                we provide a simple mechanism that allows our
                system to recallibrate when we know the room is
                empty so that it can adapt dynamically over time.},
      URL = {http://terraswarm.org/pubs/491.html}
  }
  

Posted by Anthony Rowe on 8 Feb 2015.