When one sees a car equipped with an automatic steering system, he notices that the steering wheel is moving by itself, and feels as if there is a group of wizards controlling the car, but in reality a group of advanced assistance systems are to control the car. car, and they obtain their information from sensors that closely monitor the environment of the car.
In the new Mercedes-Benz S-Class, the Drive Pilot assistance system drives the car alone on highways up to a speed of 60 km / h. It is being promoted as a traffic management assistant – with a myriad of different sensors.
“The car does not take over the leadership unless the external conditions are met,” says Gregor Kugelman, director of driver assistance systems development at Mercedes.
The stereo camera is one of the sensors for the automated driving system, and Professor Christopher Stiller, from the Department of Measurement and Control Technologies at Karlsruhe Institute of Technology (KIT), explained that this camera is similar to the human eye, no matter how the car already is. need more than just two lenses to get a look. Including the vehicle’s environment.
The German professor confirmed that “stereo” cameras see what the human eye sees, such as traffic signs and the colors of traffic lights and road signs, but what is wrong with “stereo” cameras is that they do not see for a very long distance; With a maximum speed of 80 meters, this distance is short when driving at high speeds.
Radar systems are better than stereo cameras when it comes to viewing at long distances, but these systems – as explained by German professor Christopher Steller – do not recognize the colors of traffic lights, road signs or lane markings. Radar in motors since 2000; It is used, for example, in a speed regulator that maintains a safety distance.
“Radar systems can measure speeds well, and they are ideal equipment for detecting moving objects,” added Markus Linkamp, professor of motor engineering at the Technical University of Munich (TMU).
Unlike radar systems, the way lidar sensors work seems a bit futuristic; These systems do not emit microwaves, but rather emit combined laser beams, so these sensors scan individual points in the series around the car, and the distance is measured by the time between transmission and reception.
Lidar systems create a picture from these many reflections; It collects about one million pixels per second, creating a three-dimensional (3D) point cloud, which displays the surrounding area at a higher resolution than the radar image, and lidar systems can image complex objects and distinguish pedestrians from cars in traffic.
Lidar sensors recognize to a limited extent trajectory marks of reflections, but not at all the colors of traffic lights.
German professor Christopher Stieler added that “the biggest advantage of lidar sensors is the early detection of pedestrians, which emit less reflections than cars or motorcyclists.”
Usually each type of sensor has advantages and disadvantages, but when these types of sensors are combined, automatic control functions can be provided.
The lidar sensors are located in front of the Mercedes car to display the range around the car in 3D, in addition to the presence of a radar to measure the speed and the safety distance between the car and the vehicles in front of it, and there is a “stereo” camera on the windshield to take pictures, and the camera installed in the cabin can: Recognize the amount of attention and alertness of the driver of the car so that he does not fall asleep while do not drive.
The German company installed a sensor in the wheelhouse to identify precipitation on the road while walking; Because in case of heavy rain, the driver has to take over the leadership, and on the roof of the car there is a sensitive antenna that transmits the location of the car accurately based on high definition maps.
For close range of the car, the ultrasonic sensors detect if there are people near the car, such as children playing around it, and the camera installed on the rear window and microphones recognize blue light and emergency vehicles to make sure the car – for example – do not drive in a lane Emergency traffic in emergency situations.
The Federal Automobile Office has been announcing this new post for Mercedes since December 2021, as it is the first company to authorize this post corresponding to the third tier (Level 3) of automatic driving functions classified in 5 tier, and the German company provides it works within the optional equipment package.For her S-Class car it costs 5950 euros.
Professor of Automotive Engineering, Marcus Lincamp, expects that in the future all cars will be equipped with automatic driving sensors, however the sensors will not change into Level 4 cars equipped with the “fully automatic driving” function, but changes will take place in the algorithms and system software that will take over the driving process on the road permanent highways.