Traditionally, one technology was used to protect or monitor a certain area most of the time — surveillance cameras. However, this often created false alarms or blind spots. “Camera technology with video content analysis (VCA) does people counting and barrier perimeter detection for indoor environments. But if you get into an outdoor environment, sometimes cameras are affected by light. Even a thermal camera can be impacted by ambient temperature and movement of air,” said Jacques Vaarre, MD at Optex Europe
“A single sensor could start to allow false positives, and adding a complementary system can allow the false positives to be double checked and alerts and alarms stopped before being sent out,” said Douglas Bellin, Senior Manager of Industrial Markets at Cisco Systems. “Take for example a gauge is telling you one thing, but there is only one way to verify this — which is by physically seeing what is happening in that area. The video stream could be looking at the gauge and allow remote viewing, but also allow the same video stream to allow sight verification of the environment around the area.”
Now, the benefits of fusing technology together in an integrated system, creating an extra layer of security and verified responses have gradually come to light. In the same sense, sensors have also made its way to benefit users for multiple purposes.
Driven by gun shooting and terrorist attacks, audio sensors have gained popularity, especially in the U.S.There are various gunshot detection systems on the market that help prevent this. “Audio analytics including gunshot detection — both indoor and outdoor — are growing areas of interest, particularly where integrated systems are using lockdown and threat level management capabilities,” said David Ella, VP of Product Marketing at AMAG Technology
Audio sensors working with surveillance cameras are a simple way to deal with the growing issue of gun violence. “People don’t just use their eyes to understand their environment — they use their other senses as well. We do the same with our analytics,” explained Rustom Kanga, CEO of iOmniscient
. For instance, a video might show a person falling down; the operator’s first instinct would be to send help. At the same time, an audio sensor might detect a gunshot in which case the operator may warn people not to go close to that areA and instead contact the police. “The additional information can be used to understand whether a scene is benign or dangerous,” added Kanga.
Similarly, Sonitrol New England’s audio-based — not motion-based — intrusion detection system allows operators to listen in when an alarm is triggered. If a break-in is in progress, the operator can immediately dispatch the police and relay real-time verified information to the responding officers. “Unlike a traditional burglar alarm with motion sensors that only detect what is right in front of them, our intrusion prevention audio sensor technology provides complete wall-to-wall, floor-to-ceiling coverage,” explained Joel Zimmerman, VP of Operations at Sonitrol New England.
Chemical sensors are able to detect gas leaks, drugs, spray paints, pollution and other factors that are important for an environment. “A metro railway system recently wanted to detect fires in their tunnels before they actually started. This was achieved by implementing a smell analytics system that could detect the smell of smoldering insulation plastic, as electrical short circuits were the primary cause of fires for them,” explained Kanga.
Retail People Counting
In retail, people counting is a popular tool that retailers use to gather data on their consumers. However, deploying a VCA-enabled camera alone can lead to flaws. If the camera is positioned at an angle, the accuracy of the people counter is likely to decrease, being unable to detect a smaller person hiding behind a larger person, or misidentifying an object as another person.
Alex Yeung, Product Development Manager at Zebo Asia, a systems integrator and distributor based in Hong Kong, explained the benefits sensors have when used in people counting applications. “By using a specific laser detection technology and installation technique, we can identify how many people are moving in or out of a predefined area, and we can even count the estimated number of people in the predefined size of area. Retail business depends on the customer flow and dwell time of the customers inside the shop. Performance analysis can help retailers focus and allocate the right resources in each retail shop.”
Additionally, being able to monitor in real time the number of people in the shop enables the retailer to control the environment to save energy — by auto adjusting the temperature, or slowing down the escalator if needed.
To help with this issue, Optex offers Akribos
, a 3D video-based network people counting sensor. The multidirectional, 3D modelling, video-based people counter is specifically designed not to record video, but to provide a count of how many people cross the field of view.
To sensors and beyond
Sensors will continue to improve in quality as they become more specific and robust. Many companies have already found novel types of sensors for sensor applications, be it for security or for consumer use. It's exciting to see how sensors will continue to develop in the realm of security.