Speed Measurement
ITC-EYE™ – is a software and hardware complex, intended to be used in stationary traffic control stations for purposes of radar-free speed measurments of the vehicles, passing control zone of a specially designed camera.
How does ITC-EYE™ work
Speed is measurment is based on separate measurement of distance a vehicle travels within the control zone of the camera and time it took to travel this distance. Movement of the vehicle in a control zone of the camera is measured not at random, but via a fixed point – center of a license plate. All measurements are taken based on two images, where vehicle’s license plate is visible.
Software captures first image where license plate is identifiable (entry into control zone), capture time is recorded. Then, based on the speed of the vehicle, next several images of a vehicle with a visible license plate are captured until a vehicle leaves field of view of the camera. Software captures the last image of a vehicle, where license plate number is identifiable (departure from control zone), capture time is recorded. By counting the number of images between the first and the last, software calculates time it took the vehicle to travel through the control zone, taking into account the interval between frames.
Software of the complex has an image stabilisation algorithm, intended to compensate vibrations of the structure, where video block of the complex is installed. Vibrations of the base structure caused by moving vehicles or wind may interfere with precision of measuring the distance travelled. Therefore, before calculating distance via images, stabilization algorithm is implemented in order to compensate for effects of vibration. Then, distance, travelled between the first and the last captured image is calculated. In order to do so, coordinates of a base point (center of a license plate) are calculated in the coordinate grid of the first and the last image. Images are virtually superimposed and vector of movement of the license plate is constructed within coordinate grid.
Using parameters of mutual location of a camera and control zone, established during calibration, softwarte converts image pixels into millimeters of control zone on the road.
During conversion of coordinates of pixels into coordinates of a control zone, system takes into account that projection of different pixels onto the road surface may have varying dimensions, not only along Y axis (along the road), but also along X axis (across the road). This allows to make precise calculations along 2 axiss, therefore making it possible to install the camera not only directly above the traffic lane, but also at a 30 degree corner.
This calculations would have been final, if the base point would have travelled along the surface of the road. In reality, however, license plate is attached to a vehicle at a certain height above the road. This means that actual distance travelled by a base point is shorter than one projected to the road surface. License plate is attached to the vehicle between 300mm and 1200 mm (sometimes up to 2000mm) above the road, i.e. height is not known for the particular vehicle. Therefore, without measuring the height of license plate attachment, speed measurement will be imprecise as it contains additional inaccuracy, software accounts for that, when producing end result. ITC-EYE™ has a unique algorith, which allows to calculate height, at which license plate is attached, which allows to perform highly accurate speed measurments.
Features of ITC-EYE™:
- Measurment of speed between 1 and 300 km/h;
- maximum inaccuracy of measurment under most adverse conditions is no more than ±2 km/h;
- independent measurment of speed of all vehicles inside the frame;
- hight of license plate attachement is calculated by special software independently for each vehicle;
- possibility of assignment of measured speed to a wrong vehicle is excluded;
- camera may be installed on the arch above the road or on a console beside the road. Camera may be shifted considerably away from the centerline of a controlled lane. Instalation „across the lane” is possible. Maximum possible angle is – 30 º;
- measurment can be made regardless of direction of movement using front and rear license plates, both oncoming and moving away;
- measurment is made with any supported license plate type, including two-line, regarless of color shape, size or country. Presently around 380 types are supported;
- external factors do not influence accuracy of measurment;
- camera can not be remotly detected by any devices.
ITC-EYE™ Metrological and technical data:
- interval of speed measured, km/h 1…300
- maximum measurment inaccuracy, km/h ± 2
- instalation height, m 4,5…11
- vertical instalation angle relative to road surface, …° 12…30
- horizontal angle relative to traffic vector, …° 0…30
- power supply: – alternating current (200…240) V, (50±2) Hz
- wattage,consumed with climate support (heating and/or cooldown) of camera and computer, WА, no more than:
- average nonfailure operating time, no less than, h 10 000
Working conditions:
- ambient temperature, ° С -40 to +50°
Wide range of speed measured
Maximum speed, measured by АПК ITC-EYE™ is 300 km/h. At this speed system is able to take at least 2 images of a license plate, identify it and measure the speed within a permissible margin of inaccuracy.
Minimum measured speed is not limited as system is able to register slow moving and stationary vehicles. But as it is conventional to use whole numbers to indicate speed, minimum speed level is set to 1 km/h.
Simultaneous speed measurement for several vehicles
If several vehicles shall enter a control zone of the camera, speed of each one will be measured independently. Unlike the radar, ITC-EYE™ does not emit radio signāls but measures speed, based on the movement of license plate. Hence, regardless of number of license plates in the control zone of the camera, speed of each one will be meaasured independently.
Calculation of license plate attachement height
Vehicle speed measuring devices that operates without the radar uses attachment height of the recognized license plate above the road in order to calculate the distance travelled. Some obsolete models use statistical average attachment height. In many cases average height does not correspond to actual height, which adversely affects precision of the measurements.
ITC-EYE™ calculates license plate attachment height independently for each vehicle, which insures high precision of measurement.
Possibility of error of assigning measured speed to a wrong vehicle is completely excluded.
Radar based measuring devices have a draw-back, inherent in the construction: speed is measured by one device, while image is taken by another, which often results in situations, when speed of one vehicle is measured, but another one is pictured ITC-EYE™ completely excludes such possibility due to it’s operating principle. Speed is measured via movement of the license plate movement and the license plate unambiguously identifies the vehicle. Therefore, if license plate is correctly recognized and the speed was measured, then it belongs to the vehicle.
Less strict requirements to the place of measuring camera installation
ITC-EYE™ measuring camera may be installed on the arch above the road or on the console beside the road. Unlike other means of measurement, such as radar or laser, camera may be installed at the significant angle towards the road. Angles of up to 30° are permitted.
Measurement of speed regardless of the direction of movement
ITC-EYE™ measures speed regardless of the direction of movement within control zone of the camera – both oncoming and moving away, using front and rear license plates.
Large number of license plates supported
Speed is measured via all supported types of license plate, including two-line, regardless of shape, colour and nationality. Presently around 380 types are supported: all CIS and Baltic countries (including obsolete USSR plates), all European countries (including discontinued types), 5 Latin American countries, Australia, Singapore, India etc.
No influence from external factors
Radar based measuring devices emit radio signals that may be picked up by detection equipment. This decreases efficiency of the radars as the means to identify offenders.
ITC-EYE™ emits nothing and looks like a regular CCTV camera. Radar detectors can not detect a measuring camera and offenders will be registered.
Camera is attached statically at the height of 4.5 to 11 metres and watches over a certain section of the road – a control zone. ITC-EYE™ software, installed to the computer, processes images, taken every 40 ms, identifies vehicles with license plate, travelling through the control zone and measures their speed.
Application of ITC–EYE™:
- Transgression of the speed limit;
- driving through the intersection or crossing the stop-line at the interdictory signal of the traffic light;
- driving through the railroad crossing at the interdictory signal of the traffic light;
