Today a netizen asked me a question, saying that driving the BMW 7 Series to a speed of 120 km / h, suddenly killing the steering wheel, will it overturn?
If I said no, would you believe it?
I think you will certainly not believe it, and the majority of netizens will not believe it. You will all say that this is not nonsense, 120 km / h speed, the direction of the blow is not overturned, you think the BMW 7 Series is a tumbler? We watch movies, TV, in the case of the speed is not very fast, a dozen steering wheel cars overturned; on the road to see various traffic accidents, you can also see a lot of overturned, how do you say that it will not overturn?
But I'm pretty sure to tell you: it's true, cars aren't so easy to turn over today! Let me tell you why BMW doesn't roll over in this situation.
In fact, not only bmw 7 series sedan, now the vast majority of models, when driving at high speed, directly kill the steering wheel, or turn the steering wheel sharply, the car will not overturn, but will try to correct the direction, so that the car as far as possible to maintain a straight line. In this process, the wheels of the car may leave the ground, may be a large tail flick, side slip, drift or even in place to rotate, etc., the posture may be ugly, but it will not overturn.
Why?
Because today's cars basically have an anti-roll stabilization system, abbreviated as ARC or RMI. It is one of the active safety systems of automobiles, which is a function extended from the automotive electronic stability control system (ESC/ESP), which can effectively prevent the car from rolling over. Now most of the models are equipped with this system, especially SUV models, its center of gravity is relatively high, it is easier to roll over, so this system is almost the standard of SUVs. However, this function is generally integrated with the electronic stability control system (ESC/ESP) of the car, and the average car company rarely advertises it. Its cost is not high, generally between 500 and 1000 yuan. Of course, there are also a small number of car companies in order to save these hundreds of dollars and reduce the equipment, such a car is relatively easy to overturn.
The car anti-roll stabilization system sounds quite tall, which makes people feel very mysterious, in fact, its principle is relatively simple. Gyroscopes or lateral and longitudinal acceleration sensors are installed on the body, which dynamically record changes in the tilt angle of the vehicle and the speed of changes. Based on these parameters, the on-board computer determines whether the car is at risk of tumbling during driving. If it is determined that the car is in danger of rolling, the on-board computer will immediately reduce the engine output torque, and quickly adjust the braking force distribution of the wheels on both sides, so that the car can restore balance in the shortest possible time and prevent the rolling from occurring.
How powerful is this automotive roll stabilization system? There was once a car company, the name I forgot, they developed a model, and it was equipped with this system. When the car was publicly tested, it was declared: No matter who can turn the car over, the reward is 100,000 US dollars! As a result, many media reporters and test drivers, no matter how toss the car, it is like a tumbler, just don't roll over. And now the car, more advanced than it, want to turn the car over, is very difficult, or almost impossible to do.
Of course, whether the car is turned over does not mean that it does not overturn. If the car suddenly hits an obstacle while driving at high speed, it is still possible to be overturned, which is why we can see the overturn in a traffic accident. In addition, the car anti-elk test results are poor, does not mean that the car will roll over, elk test, even if the rear wheel side slip tail, the car is only horizontal sliding not in accordance with the prescribed route only, not said not to go will overturn.