Optical Turnstile Innovation

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In the past, security turnstiles have been limited to narrow lanes that constrict the flow of people to one person at a time, so that controlled access can be achieved by blocking the passage of unauthorized individuals. The trouble with that approach is that the majority of individuals are authorized, with unauthorized passage attempts being the exception.

It doesn’t make sense to slow down all traffic by using narrow single-person lanes just for the exception cases that infrequently occur. Additionally, the wider lanes and entryways limit the impact of the slow or stop-and-go behavior of an unauthorized person, and easily accommodate individuals with rolling cases, luggage, boxes, and other business-normal variations to the usual single-person traffic.

The new dViator™ product from Digicon is a brilliant innovation to their dFlow™ turnstile/pedestrian gate control line. It can provide wide turnstile aisles that multiple authorized people can traverse through at high speed and when unauthorized people enter the turnstile, they are prevented from entering the access-controlled area and are instead guided to a security inspection point or back in front of the turnstile. The video below shows dViator in action.

Advanced Technology from Autonomous Vehicle R&D

To achieve this kind of performance, dViator makes a 3D model of the pedestrian scene in front of a secure area’s entrance point, by using an overhead eye-safe near-infrared light emitter and sensor and applying the Time-Of-Flight (TOF) measurement technique to the reflected light. TOF is a method of determining distance based on the known speed of light, measuring the time-of-flight (travel time) of a light signal sent between a light emitter and reflected back to the light receiver sensors from object surfaces in a target area.

The security industry is just catching on to Time-Of-Flight measurement and scene modeling, which is a strong area of research and development for autonomous vehicles. To see what a TOF sensor looks like, see this 2-minute video from Melexis presenting its new TOF chipsets, one already in use by BMW. For more in-depth technical information,  there are two two presentations from AutoSens, the world’s leading vehicle perception conference and exhibition, held at AutoWorld in Brussels, Belgium: one 23-minute presentation (2017), and one 32-minute presentation (2016) from Sony Depthsensing in Ixelles, Belgium. It is an important area of emerging affordable technology.

High-Volume Optical Turnstiles

The dViator turnstile innovation is an example of an emerging category of 21st century security products that apply smart sensors and advanced real-time analytics to gain much higher levels of product performance and security-effectiveness than has been possible with 20th century technology. It can distinguish between a single person with a backpack, luggage or a stroller and two people close together or touching. It can track multiple people in the entry zone, which can be as many as 7 or 9 people, depending upon the size of the area. It requires access control system integration, which can be accomplished via traditional general-purpose input/output connections (GPIO) or via an SDK for a richer integration that includes additional data for the access control system.

The video above shows the wide lane option which is ADA compatible. Lane widths are customizable, but Digicon suggests as a default that all dFlow and dViator lanes be ADA compatible. Notice in the video how the speed of the turnstile’s control barriers is slow or fast, based upon the speed of travel of the offender, which is made possible by the high-speed processing of the sensor algorithms. Notice how authorized users go quickly into the secure area because that is the default open-channel configuration of the turnstile. When unauthorized users arrive, you can see how the exit end of the turnstile lane reconfigures to shift one or more offenders into a screening area or back to the entrance area.

Because wider lanes can accommodate a full range of pedestrian traffic faster, often fewer lanes are needed at an entrance.

To do this, dViator uses its overhead sensor to create and maintain a real-time 3D map of the turnstile area, tracking each individual within the turnstile and visually displaying their location position on an LED-powered colored light band display that provides a separate color band for each individual group in the turnstile. The light bands can be configured, for example, to use one color for a university’s employees and teaching staff and another color for students. Unauthorized individuals get a red band so that the moment they enter the turnstile, they can know they are identified as unauthorized and are being tracked.

The locator band follows pedestrian motion exactly, whether they move forward, back or stop. If they stop in a wide turnstile lane, other individuals can move past them and the overall flow through the lane continues. A display monitor can inform unauthorized users of the reason for their denial of access and instruct them where they should go next – all of which occurs outside the turnstile lane, while the ordinary flow of people continues.

More Prevention Than Detection

The dViator time-of-flight sensor cannot be fooled by techniques that trick traditional light-sensor-based optical turnstiles, because the dViator’s analytics distinguish between each individual in the 3D scene and never lose track of unauthorized individuals despite their attempts to fool the system. In my opinion, this represents the level of accuracy and strength needed to affordably addressing tailgating.

Ray Bernard, PSP CHS-III, is the principal consultant for Ray Bernard Consulting Services (RBCS), a firm that provides security consulting services for public and private facilities (www.go-rbcs.com). Mr. Bernard is a Subject Matter Expert Faculty of the Security Executive Council and an active member of the ASIS International member councils for Physical Security and IT Security. Ray was recently named as one of the Top 20 IFSEC 2018 Global influencers in the security thought leadership category.