Radar systems on vehicles are a new system of active safety on the vehicle. The beginning of use was in vehicles of a high and higher class, and recently it has taken an increasing share in both, the middle and lower segment of vehicles. As a result, it gained in the mass application, and at the same time increased active traffic safety. In combination with lane-change systems, traffic sign recognition, and emergency braking assistance, it is better known as the ADAS system (Advanced Driver Assistance System). Modern technology has enabled the rapid exchange of information within various systems on the vehicle via optical cables so that the reaction of the system itself sometimes takes action to prevent or reduce accidents independently of the driver.
The only vehicle through the radar beam follows the movement of vehicles in the lane by the driver selected. Any change in the lane, which the driver "did not announce to the system" by giving a turn signal, the system will correct and return the vehicle to the original direction of travel. Also, if a sign recognition system is present, the vehicle will only adjust the speed according to the set signalization.
The braking assistance system, based on the information of the radar beam reading and the speed of the vehicle, calculates the safe stopping distance of the vehicle and the braking force to prevent the vehicle from crashing into an observed obstacle of any kind. If the driver has not taken the action of decelerating the vehicle himself, the system, via the ABS, starts the deceleration independently, and if necessary, stops the vehicle at a safe distance. If an accident is inevitable, the vehicle will be slowed down so that the consequences of the accident are as low as possible, ie to prevent the death of the participants in the accident.
The radar beam itself is placed by the vehicle manufacturers in the front part of the vehicle under the hood of the vehicle at a height of 260 - 1000 mm, measured from the pavement. The orientation of the radar beam is the longitudinal imaginary axis of the vehicle itself.
The front radar is intended for work on a vehicle with an unlimited shelf life. Like every vehicle assembly, it is subject to inspection, adjustment, and, if necessary, its replacement. It is especially useful during bad weather and reduced visibility, heavy rains, fog, heavy snowfall, reduced visibility, and night driving.
Control and adjustment must be performed at each major service interval for vehicle maintenance, as prescribed by the vehicle manufacturer. Replacement of the radar beam sensor is mandatory in the event of an accident on the vehicle, and adjustments after minor repairs to the body parts of the front of the vehicle or replacement of the radar beam sensor.
Calibration of the radar beam sensor is required in case of an incorrect reading of the radar beam, change of the shock absorber on the vehicle or parts of the vehicle chassis, and replacement of the windshield, as well as the search for an electrical fault on the vehicle.
Depending on the vehicle manufacturer, the calibration of the radar beam sensor can be performed by the static method in the workshop, but with some manufacturers, it is necessary to perform a dynamic test or calibration of the radar beam while driving.
For an accurate radar beam, properly adjusted vehicle optics of the front and especially the rear wheels are of utmost importance. If the vehicle's optics are not adjusted to the vehicle manufacturer's values or the vehicle is modified outside the vehicle manufacturer's permitted values, the radar beam will change its field of action. In this case, it can easily happen that on a straight road the vehicle starts to slow down, regardless of the driver's will, because the radar beam instead of the vehicle in front of it read the movement of the vehicle moving in the opposite lane towards it. Also, since the height of the radar beam sensor position has changed, the angle of inclination is wrong so that the radar beam may not read the obstacle in front of the vehicle, and all associated active safety systems simply do not respond, or they respond with reduced efficiency or delay.