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Space is a valuable commodity, and underusing it is a waste of money. Research estimates that many businesses can reduce their space needs by around 30%. Counting people flow into and out of a workspace is key for space utilization initiatives. This article outlines currently available technologies and the latest developments in people counting.
Businesses could save around $1.5 trillion in reduced rental costs by utilizing wasted space. Smart technology can help identify under-occupied areas and improve utilization while enhancing employee wellbeing and efficiency. The first step of space optimization is understanding exactly how an area is being used. This requires robust methods to count and track people within a property.1
However, smart systems that count and track people within an office can do much more than just inform space saving initiatives. They can adjust heating, air conditioning, lighting, and other environmental parameters depending on the actual occupancy of a room, resulting in lower utility bills. They can also inform employees about where they can find available working spaces. In retail businesses, people tracking systems can be used to count footfall and optimize shop layouts.2
Monitoring the Flow of People is an Integral Part of Smart Office Systems
Traditional people counting processes involved a person standing with a clicker physically counting people as they passed. As you can imagine, this is a job that is tedious and prone to errors. Thankfully, a wide range of technological solutions for people counting is now available, utilizing a range of cameras, sensors, and trackers.3,4
Wi-Fi tracking uses the signal from people’s mobile phones and other devices to sense their presence. The problem with counting people using this method is that people may not be carrying a device, their device may be turned off, or they may have several devices, making counts inaccurate. Furthermore, Wi-Fi-tracking relies on triangulating signals to determine a person’s location, which is not very accurate in small spaces.5,6
Ultrasonic sensors bounce sound waves off people as they walk past. They make a very cost-effective solution but can only offer limited accuracy. They generally can’t distinguish objects and can be confused by textured surfaces that don’t reflect sound waves as expected.3
Single beam infrared sensors project a beam of infrared light across a doorway. When a person breaks the beam of light by passing through the doorway, their presence is detected. Single beam sensors only offer limited accuracy as they cannot distinguish multiple people walking together. They also do not record whether a person is entering or leaving the room.7
Thermal cameras use people’s body heat to detect their presence. They use motion to distinguish people and can record which direction a person is moving in. However, they can struggle to count people accurately if they stand still, walk close to each other, and if the ambient air temperature is close to that of a human. They are also prone to error when, for example, the door of an air conditioned building is opened on a hot day.3
CCTV people counters rely on installing software into existing CCTV systems. As CCTV systems typically use one camera to count people, they suffer from reduced accuracy due to a lack of depth perception and interference from environmental factors such as shadows. installations are typically aimed at security concerns and are often not positioned in the optimal way for people counting duties. There is also a growing concern over privacy and GDPR compliance due to the fact CCTV cameras capture images of people’s faces, which enables identification.3,5
Stereovision people counting systems use two cameras to provide depth perception and improved counting accuracy compared with single-camera solutions. Stereovision is more expensive than other people counting technologies and is still limited by environmental conditions such as ambient lighting conditions.3,5
Time-of-Flight Technology is Revolutionizing the People Counting Industry
Time-of-flight (ToF) cameras provide 3D information in a package that is simple, fast, easy-to-install, simple to use, compact, and cost-effective. ToF technology has found a range of applications in robotics and autonomous vehicles, and now it is disrupting the people counting industry.8
ToF cameras consist of a lens, an integrated light source, a sensor, and a computer interface. They illuminate a scene with pulsed light. Objects in the scene reflect the light back to the sensor. ToF cameras measure the time taken for light to travel from the source to the scene and then back to the detector. From these measurements, the distance to all the objects in an image can then be determined. ToF cameras capture depth and intensity information simultaneously for every pixel in the image, resulting in high frame rates and unrivaled accuracy.8,9
While ToF cameras can suffer from interference from scattered light, light that has been reflected multiple times, and bright ambient light, there is no better way to capture the 3D information needed for accurate people counting.8
Terabee are Experts in ToF Sensing Solutions
Terabee provides ToF hardware and the necessary SDK (Software Development Kit) so that users may write their own software applications. A complete people counting solution is in the works and due to release in 2020 for users wishing to acquire a plug-and-play off-the-shelf solution. Their ToF technology offers a reliable, compact and cost-effective solution. Their cameras capture the unseen and can even operate in darkness while preserving privacy and remaining GDPR compliant.9,10
Terabee 3Dcam 80x60
Terabee is developing their own people counting algorithm for ToF that targets 98% accuracy, or better. The upcoming Terabee ToF people counting software solution will be able to count multiple people entering or exiting a room while rejecting stationary objects and background features.11
Terabee offer two ToF cameras, the Evo 64px is ideal for standard doors, and the Terabee 3Dcam 80x60 is well suited for monitoring larger entryways. Whether you are looking for a 3D camera to integrate into your own people counting solution, or you are looking for a complete people counting package, Terabee can help.11,12
References and Further Reading
- ‘Global businesses could collectively save up to $1.5tn through efficient use of office space, finds Philips’ https://www.worldgbc.org/news-media/global-businesses-could-collectively-save-15tn-through-efficient-use-office-space-finds
- ‘Smart Buildings Systems for Architects, Owners and Builders’ — J.M. Sinopoli, Elsevier, 2010.
- ‘A Survey of Human-Sensing: Methods for Detecting Presence, Count, Location, Track, and Identity.’ — T. Teixeira, G. Dublon, A. Savvides. ENALAB Technical Report, 2010.
- ‘IoT-based Occupancy Monitoring Techniques for Energy-Efficient Smart Buildings’ — K. Akkaya, I. Guvenc, R. Aygun, N. Pala, A. Kadri, IEEE, 2015.
- ‘Building occupancy estimation and detection: A review’ — Z. Chen, C. Jiang, L. Xie, Energy and Buildings, 2018.
- ‘Indoor occupancy tracking in smart buildings using passive sniffing of probe requests’ — E. Vattapparamban, B.S. Çiftler, İ. Güvenç, K. Akkaya, A. Kadri, IEEE, 2016.
- ‘A Field Guide to Office Technology’ — E. Sobey, Chicago Review Press, 2007.
- ‘Time-of-Flight Cameras: Principles, Methods and Applications’ — M. Hansard, S. Lee, O. Choi, R.P. Horaud, Springer, 2013.
- ‘Time of Flight Principle’ https://www.terabee.com/time-of-flight-principle/
- ‘3D ToF Cameras’ https://www.terabee.com/sensors-modules/3d-tof-cameras/
- ‘Build People Counting Applications with Terabee 3DCcam 80×60’ https://www.terabee.com/build-people-counting-applications-with-terabee-3dcam-80x60/
- ‘TeraRanger Evo 64px’ https://www.terabee.com/shop/3d-tof-cameras/teraranger-evo-64px/
This information has been sourced, reviewed and adapted from materials provided by Terabee.
For more information on this source, please visit Terabee.