Video Detection Sensor for Vehicle Presence Basic Principles

Video Detection Sensor for Vehicle Presence Basic Principles, Selection, Installation & Configuration THE Reference in Traffic Video Detection 1

Video detection: Detection zones on video image Trafi. Cam: Vehicle presence THE Reference in Traffic Video Detection 2

Functionalities ü Basic functionality = vehicle presence ü Alternative functionality = count (number of pulses) = zone occupancy (length of pulses) THE Reference in Traffic Video Detection 3

Selection: 2 lens types ü Trafi. Cam “Wide Angle” (focal distance = available 3 mm): o Detection at close range (0 -25 m), with a wide camera view o Rather vertical camera position o Typical camera height: o side fired: 3, 5 -8 m o overhead: 5 -8 m ü Trafi. Cam “Narrow Angle” (focal distance = 8 mm): o Detection at a longer distance (15 -75 m), with a wide camera view, but zoomed in o More horizontal camera position o Typical camera height: o side fired: 8 -12 m o overhead: 6 -10 m THE Reference in Traffic Video Detection 4

Camera View Trafi. Cam “Wide Angle” 0 -25 m 4 lanes THE Reference in Traffic Video Detection 5

Camera View Trafi. Cam “Narrow Angle” 15 -75 m 4 lanes THE Reference in Traffic Video Detection 6

Trafi. Cam Wide Angle vs Narrow Angle Wide Angle THE Reference in Traffic Video Detection 7

Example Trafi. Cam Wide Angle Three lanes, stop bar detection, Trafi. Cam overh THE Reference in Traffic Video Detection 8

Example Trafi. Cam Narrow Angle Three lanes, advance detection, Trafi. Cam overh THE Reference in Traffic Video Detection 9

Installation no horizon in the image THE Reference in Traffic Video Detection 10

Installation be aware of optical occlusion! 5 m camera height, no offset 9 m camera height, no offset - on the same lane Offset = distance from the edge of- on adjacent the road lanes 5 m camera height, 2 m offset THE Reference in Traffic Video Detection 11

Installation vertical or horizontal mounting üMount on solid infrastructure üFixation with bolts or (stainless steel) bands Try to avoid camera movement. This could decrease the detection performance! THE Reference in Traffic Video Detection 12

Examples Vertical Mounting THE Reference in Traffic Video Detection 13

Example Horizontal Mounting THE Reference in Traffic Video Detection 14

Example Alternative Mounting THE Reference in Traffic Video Detection 15

Configuration optimal size of detection zone = slightly exceeding size of a regular car Multiple detection zones per lane possible to cover a larger Size regular car: about 2 m area wide & 5 m long THE Reference in Traffic Video Detection 16

Configuration Direction sensitivity Make a zone direction sensitive only to avoid unwanted detections A direction sensitive zone could decrease the detection performance THE Reference in Traffic Video Detection 17

Configuration Vehicle headlights in detection zone detection during daytime: on vehicle detection at night: on vehicle headlights THE Reference in Traffic Video Detection 18

Configuration Advanced settings: ü Use headlight reflection suppression only when strong reflections are expected ü Use tree shadow suppression only when strong tree shadows are expected ü Use camera movement suppression only when significant camera shaking is expected THE Reference in Traffic Video Detection 19

Traficon nv Tel. : +32 (0)56 37 22 00 Fax: +32 (0)56 37 21 96 E-mail: traficon@traficon. com www. traficam. com THE Reference in Traffic Video Detection 20