What is ACC automotive technology?What is ACC automotive technology?

What is ACC automotive technology? Detailed ACC terminology

Many people do not understand some English technical terms on cars, and do not know what functions they are, such as what technology is this ACC? What does ACC technology mean in Chinese? Wait, Yi Maojun will help you explain!

ACC usually has two meanings in a car.

ACC is the key door switch

Literally means accessories. In the car, ACC means that before the car is started, if there is a key in the ACC position, as long as the key is set to this position, some devices that do not use much electricity, such as radios, cigarette lighters, etc. It is powered on. When the car is ignited, a strong current is required. At this time, the ACC bit stops power supply, and when the car finishes ignition, it starts to supply power again.

The general car key has 4 gears, one is “OFF”, one is “ACC”, the other is “ON”, and the other is the starting gear, but some models (like Red Flag, Audi, etc.) have 3 gears. Gear, that is, there is no “ACC” gear.

The “OFF” position is “Off”, disconnecting the car power supply;

“ACC” gear is “You can power some electrical appliances in the car without starting the car”;

The “ON” position is “powering all electrical appliances in the car”. The starting position is a self-resetting switch. After starting the car, it automatically returns to the “ON” position.

Another meaning of ACC is: adaptive cruise control

The English full name of ACC is “Adaptive Cruise Control”, and Chinese means “Adaptive Cruise Control”. The adaptive cruise control system is an intelligent automatic control system, which is developed on the basis of the existing cruise control technology.

While the vehicle is running, a distance sensor (radar) installed in the front of the vehicle continuously scans the road in front of the vehicle, while the wheel speed sensor collects the vehicle speed signal. When the distance from the vehicle in front is too small, the ACC control unit can coordinate the action with the anti-lock brake system and the engine control system to properly brake the wheels and reduce the output power of the engine to make the vehicle and the vehicle in front. Always keep a safe distance.

When the adaptive cruise control system controls the vehicle’s braking, the braking deceleration is usually limited to a degree that does not affect comfort. When a greater deceleration is required, the ACC control unit will send an audible and visual signal to notify the driver to take the initiative to take control. Operation. When the distance from the preceding vehicle is increased to a safe distance, the ACC control unit controls the vehicle to drive at the set speed.

Through the above description, we also call him “with a low-speed following mode”. This newly added low-speed following mode is specially designed for congested road conditions. It can automatically follow the car to stop and restart. This greatly eases driving fatigue when driving on congested roads and highways, and brings more fun to driving.

In addition, the auto team that we have seen is also based on this technology. It just adds some other functions such as vehicle identification and network control.

What is the ACC adaptive cruise capability?

Now many cars have begun to popularize L2 autonomous driving. In fact, it is ACC (with automatic follow-up and collision avoidance) + lane keeping, but there are still many problems. The first is greatly affected by the weather. Rain and fog are easily misjudged. At night Question marks can be used for normal use. Second, the marking lines in many places in China are not clear, and they are better at high speeds. The marking lines in the city, huh … So this is only an auxiliary function, you have to drive carefully.

At present, the solution of the widely-viewed forward-looking millimeter-wave radar + camera, the radar is actually not very concerned about fixing obstacles. Because the reflection near the ground is too cluttered, the Doppler effect is usually used to filter out reflected waves from fixed objects before target recognition. This method is more accurate for moving vehicles, but for fixed objects, it is mainly identified by cameras.

It should be noted that, for Doppler radar, the objects crossing the road are fixed objects … so at the current stage of the adaptive cruise, although the car can drive in the lane itself, the driver is still required to pay attention to the driving state at all times. In theory, just a little easier.

At present, this is mainly because the performance of these processors in the vehicle is not enough to process the original signals. The new generation of platforms has begun to be equipped with more powerful processors and high-speed buses. In addition, lidars with acceptable prices can now be mass-produced. The A8 is already at the L3 level, and it should be possible to have more practical high-speed autonomous driving in two or three years.

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