Technical Overview
The system comprises one or more CCTV cameras each associated with a Video Turnstile (VT) detection module. This recognises when someone crosses a narrow region, making it ideal for counting customers entering or leaving through a doorway. The VT module may be held in a rack with several other modules, or it might be a boxed unit.
A small rack of Video Turnstile modules
A full rack of Video Turnstile modules
A Video Turnstile boxed unit which can hold two modules
Each VT module produces two count totals: one for people going up the video picture and one for people going down. In other words, a count of people going in and a count of people going out.
The VT detection modules pass their counts to a VT Logger. The Logger can accept counts from up to 16 non-logging detection modules. It records counts over a time epoch, for example the number of people entering every 15 minutes or every hour. At regular intervals the Video Turnstile software, running on a PC, collects the counts from the VT Loggers and saves them in a text file.
In addition to counting the number of visitors, you can also discover how long a person spends in an area. To do this you need our dwell meter package.
Connections to a Computer
A Logging unit can be connected to the computer over RS232, RS485, Ethernet, WiFi or a modem. Using RS232 you connect the LVT to one of the PC's serial COM ports. This is suitable when the LVT is close to the computer. For greater distances or greater numbers of logging units (and hence doorways monitored) the units are better connected over RS485 cables. In this case you need an RS485 output kit which includes an RS232-RS485 converter for connection to a PC. Alternatively, connection to an Ethernet or Wi-Fi network is easily made using an appropriate Video Turnstile Logger. For remote monitoring you can connect the Logging unit to a modem.
The Video Turnstile Units (Non-Logging)
Each Video Turnstile unit is a transit detector for a single video feed. It issues pulses for each transit across its field of view, so there is a pulse train for people entering and a pulse train for people leaving. From the video picture viewpoint, these are transits going up the screen and transits going down the screen. Two count channels are created by each transit detector. Pulses from VT unit are normally counted by a logger in an LVT unit; or, where simple totals are required, they can be fed into a Display Meter.
The video out signal makes setting up and validating the count a simple task. The composite video signal can be viewed on a normal TV (SCART socket adaptor supplied) and incorporates two white lines showing the edges of the transit zone. Two additional detection lines (for transits up or down the screen) flash on when a transit through the zone is detected. For examples see the video clips in the See it Working page.
The Logging Video Turnstile Units
The LVT is a transit detector for a single video feed, together with a 32 channel count logger. The logging unit connects to the PC as detailed above in Connections to a Computer.
Cameras
Low-cost, unobtrusive, closed-circuit television (CCTV) cameras are used. The basic camera can be directly mounted into ceiling tiles so the camera is flush with the ceiling. For other circumstances, dome cameras can be supplied. The cameras normally come with a standard 3.6 mm lens and are suitable for installation between 2 and 3 meters above the floor. For a higher camera, a different lens will restore the video picture to the parameters used by the detector.
Dwell Meter
The Dwell Meter detects how long customers spend in one place and how often that place was visited. With the Dwell Meter retail outlets can, for example, test the effectiveness of new displays, compare one display with another, evaluate new store layouts, investigate price elasticity or monitor waiting times at counters and checkouts. We have more information on the Dwell Meter here.
Display Meter
Instead of downloading the counts to software, you can use a Display Meter. This is an electo-mechanical counter that counts pulses from up to sixteen Video Turnstile units. It maintains the count whilst power is off. The Count can be reset to 0 by a button press, but this feature can be disabled if necessary. It can also be reset automatically at the same time each day. The meter can show occupancy - visitors in minus visitors out - or total visitor count.
Request a Quote for a People Counting System
To request quote for a customer counting system, or to discuss your application, please fill in our on-line questionnaire.