ACC Eng 04 880976
ACC Eng 04 880976
ACC Eng 04 880976
ACC is based on an advanced radar unit with a Doppler function that compares the frequency between a transmitted pulse and the returning echo.
ACC (Adaptive Cruise Control) is an advanced radarbased cruise control system that automatically helps the driver to maintain a safe distance to the vehicles in front of the truck. The system should be regarded as a comfort and safety system that further enhances vehicle productivity, particularly for long-haul transport. ACC makes it easy to follow the rhythm of the surrounding trafc. ACC enables the driver to select the time interval to vehicles that are in front of the truck. ACC then maintains this interval by automatically regulating throttle pressure and braking functions. In addition to auxiliary brakes ACC also utilizes the wheel brakes, which gives a reliable braking performance of the system. Brake blending is used and the needed mix of brakes is judged continuously. Using time as a setting for the distance offers an advantage in terms of safety. At higher speeds, the driving distance also increases. The cruise control system is based on an advanced Doppler radar. It has the capacity to detect moving objects up to approximately 180 meters. The radar function is not affected by rain, fog or darkness. However, in extreme weather conditions, the radar may become blocked by snow or ice. The driver is then alerted by a fault code in the display. The ACC works in collaboration with normal Cruise Control (CC). When there is no target in front of the vehicle the control is automatically handed over to CC and speed adjusted to set speed. As a result, ACC activation rules are the same as for CC: the speed must be higher than 30 km/h to engage ACC, and to resume ACC, after e.g. having depressed the brake pedal, the speed must be over 15 km/h.
SPECIFICATION
Designation............................................................................ ACC Radar frequency .............................................................. 77 Ghz Elevation angle radar .................................................... +/-2.5 Azimuth angle radar .......................................................... +/-6 Time interval......................................................1.5-3.5 seconds No. of detected vehicles ......................................................1-12 No. of selected target vehicles ................................................. 1 Detection capacity moving vehicles.............approx. 180 m Max. retardation ................................................................. 2 m/s2
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FACT SHEET
Adaptive Cruise Control ACC
Advanced Doppler radar with aviation technology
The ACC technology is based on the Doppler effect, which utilises the way in which a sound wave changes frequency, depending on whether it is moving towards or away from the sound source. Doppler radar utilises this principle by comparing the frequency of the transmitted pulse with the frequency of the returning echo. In this manner, it is possible to determine the speed of the object that caused the echo. This enables the ACC radar to register very small differences in speed between the truck in which is it tted and the vehicles that the truck is following.
The ACC control. The time interval can be easily increased or decreased with the knob on the stalk.
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