Quadrox VCA - Manual (Page 15)

VCA Installation and Configuration manual 15
Version 4.9 Series
3.2.2.4 Enter and Exit
This is a directional rule. The alarm is triggered when the object enters or exits the zone
borders.
3.2.2.5 (Dis)Appear
The alarm is triggered when the VCA cannot see how the object appears or disappears. E.g. a
bird came from behind a tree that was partially in and partially out of the zone; or a person
suddenly appears from behind a wall that is present in the zone.
3.2.2.6 Dwell
An object needs to hang around in a zone for the minimum specified time before it triggers the
alarm.
3.2.2.7 Direction
Direction only works in combination with the Line you can add (instead of a zone). When
crossing the line in a particular direction, the alarm will be triggered (e.g. when a car violates a
traffic sign and makes an illegal turn).
There are 2 parameters that need to be defined here as well:
 Direction (an object must be moving to trigger an alarm) between 0 and 360°
 Variance (a tolerance margin) in degrees.
e.g. a car cannot make a u-turn, but it can cross the direction line to enter a street that
lies on 45° of that direction line.
3.2.2.8 Tailgaiting
Tailgaiting is useful when monitoring a queue. The alarm will be triggered when a new object
(person) appears in the line within a specified time frame.
e.g. this is useful in a store at the POS area. The time interval is set at 10 seconds. If customers
come to the POS area with an interval of 12 to 20 seconds, the alarm will not be triggered. If
customers come to the POS are with an interval of less than 10 seconds, the alarm will be
triggered and an automated message can be send to notify that a second (or third) POS needs to
be opened to prevent long waiting lines.
3.2.3 Filters
Each object is classified as one of four object types. This can be a:
 Person: object with size less than 2m² and a speed less than 20km/h
 Group of people: object bigger in size than a person but with speed less than 20km/h
 Vehicle: object with size larger than 2m² and speed more than 20km/h
 Clutter: none of the above (e.g. birds)