The deployment of Time of Flight technology has increased in the security sector in recent years. By using 3D images instead of 2D and accurately measuring distances by calculating the time of flight of a light signal and every point of a subject, it allows smarter applications by delivering advanced information, aiding tailgating detection, proximity and intrusion sensing. SICK offers a plug-and-play option with its Visionary-T DT sensors.
The use of Time of Flight technology offers a good range of benefits to the security sector, increasingly so as a growing number of end users seek more value and day-to-day benefits from their solutions.
Time of Flight sensing offers a number of benefits over video-based information gathering in a number of applications. Whilst the devices are often referred to as ‘cameras’, the results are a world away from that of video surveillance, but in high-risk access control applications the implementation of Time of Flight devices makes a lot of sense.
Time of Flight sensors use laser technology to capture images. They are not scanning systems which use the laser to create a pixel-by-pixel image. Instead, with Time of Flight devices, each pulse of light from the laser captures details from the entire viewed scene.
While the image is usually of a lower resolution than traditional video cameras, this isn’t an issue as the devices aren’t used for the identification of people or for analysis of events. Instead the goal is to assess the presence of objects, based upon the characteristics of reflected light
Time of Flight sensors can effectively create 3D footage, because the technology allows for the capture of spatial and temporal data. This is captured via a single flash from the laser-based light source.
The Visionary-T DT sensor from SICK is a configurable, plug-and-play 3D detection sensor based on the company’s Visionary-T range of industrial 3D imaging cameras. The device makes use of the imaging capabilities of SICK’s single-snapshot Time of Flight technology for a range of detection, notification and security applications.
The Visionary-T DT sensor makes use of integral image processing, ensuring it can be added to a wide range of new or legacy installations without the need for dedicated processing hardware of additional IT-based infrastructure.
How does it work?
The Visionary-T DT sensor can easily be configured to accurately detect either the presence or absence of 3D objects. As a result, it offers a versatile and flexible entry-level option for the protection of standalone objects such as exhibits or communal assets, as well as of large and complex wall-standing or mounted items such as furniture, stored items, installations and statues.
The 3D sensors offer high levels of flexibility for indoor use (the unit is rated to IP67) due to the implementation of SICK’s innovative snapshot technology. This provides real-time information for every pixel based on time of flight measurements, even for stationary applications.
The sensors capture high-resolution real-time 3D images with one shot of light. With a sensing area range of up to 50 x 45 metres at 40 metre range, it provides good area coverage. The light burst can illuminate matt and dark coloured objects, and adjustable filters allow application-specific optimisation for enhanced detection quality.
Captured data can either be transferred from the sensor in a raw format or as pre-processed data specifically assessed for the application in question. Additionally, it is also possible to only transfer measured values, resulting in simple sensor responses.
Connectivity is via a standard Ethernet port and the unit requires a 24V DC power supply. Operational range is from 0.5 to 60 metres. The sensor has two digital inputs and four outputs.
Configuration is carried out via dedicated software. The Visionary-T DT can be set-up and adjusted using a standard PC loaded with SICK’s SOPAS software tool. Further adjustments are made using the purpose-designed graphical user interface. To simplify the process, 3D objects or detection zones can be ‘taught’ to the system from the camera without the need for complex manual programming.
Adding value
The Visionary-T DT sensor enables the automation of detection tasks that are difficult to achieve with a standard 2D video camera. The issue with two dimensional images is the lack of depth which means that important information can be either missed or concealed by other objects, making a full and proper analysis of certain situations inaccurate.
An automatic real-time assessment of objects, delivering a greater degree of salient information, can be quickly and easily accomplished in applications where the Visionary-T DT is deployed. For example, the sensor makes it a simple task to detect whether an object has been damaged, moved, had elements added to it or otherwise been affected by spurious actions.
The sensor collects 3D image data which is intelligently analysed at the sensor to provide simple and accurate conditional data based on a Yes/No or Occupied/Unoccupied status. The method of signalling this conditional information is dependent upon the user-defined configuration.
The sensor’s support for external digital outputs allows a simpler level of integration with other systems, including intruder detection or video surveillance solutions Additionally, a direct link from a digital output can be set up to initiate a visual display, local alarm or a PC-based event, enabling immediate notification of alarms. This can be backed up by recording or flagging incidents for later appraisal and subsequent action.
In summary
The Visionary-T DT sensor allows installers and integrators to add 3D vision into bespoke security systems without the need for dedicated infrastructure to process data.
As a result it delivers a wide range of value-added opportunities to easily achieve 3D detection tasks that previously would have been challenging to create with standard video cameras and intelligent video analytics.
