The most common sensor which used in the parking aid is the Ultrasound sensor. The sensor works acoustically with a limited range of no more than ten meters and a correspondingly limited application spectrum. The sensor is also used in blind-spot warning systems, along with being used as a parking beeper. The collisions are prevented with traffic behind the vehicle when lane changing has happened.
Even though the sensors are inefficient, they are inexpensive and robust. It is mainly implemented around the body and it is indispensable for future autonomous cars.
One of the most inexpensive environment monitoring systems in the car is the camera with a criterion of being dependent on good visibility conditions where darkness, fog, or heavy rain plays a huge role. Three- dimension model cameras work quite accurately with data received from sensors such as radar. Stereo cameras like human eyes are also provided with more spatial information from many manufacturers. Mainly it is used for emergency braking systems. Collisions are avoided by using image recognition software that can identify pedestrians and cyclists crossing the road.