Predict the future of 0.5s! Intelligent four-wheel drive system, quattro has done it

What is your impression of four-wheel drive?

"Getting out of trouble? Climbing? Grip in rain and snow? Safety? Acceleration? Control?"

You are right. These are more or less the benefits of four-wheel drive, because four-wheel drive solves two problems:

1. When, how and in what proportion is the power distributed to the front and rear axles?

2. When, how or in what proportion is the power distributed to the left and right wheels?

Simply put, it is a question of how the four wheels coordinate and how they exert force.

So we have the following pictures:

When accelerating, the center of gravity shifts and the rear wheels have stronger grip, so more power is distributed to the rear wheels to improve acceleration performance;

When turning, the center of gravity shifts and the outer wheel has stronger grip, so more power is distributed to the outer wheel to assist in turning;

When the car is stuck, one or more wheels spin, so more power is distributed to the wheels with grip to help it get out of trouble;

In rainy and snowy days, the grip of multiple wheels decreases, so the power is evenly distributed to the four wheels to ensure grip.

etc.

So, you know why people go to so much trouble to add four-wheel drive systems.

At this point you may want to ask a more practical question: Yes, I know that four-wheel drive is very useful, so how do I choose it?

As to the question of which four-wheel drive system is the best, it depends on your needs. If you want strong off-road capabilities, you must have the "three locks". As for coping with paved roads, in fact, the performance of each company is similar. For example, Mercedes-Benz has good low-speed escape ability, BMW, Acura, Subaru and others have good handling, and Audi quattro, like its gecko logo, is stable!

I want to talk about the Audi quattro separately, because it is different from many competitors that use multi-plate clutch differentials. It uses a Torsen differential. Its strength lies in: it uses pure mechanical self-locking between the worm gear and the worm to achieve the functions of differential and transmission, with extremely fast response speed and super high reliability. That's why I say it is stable!

However, it is not perfect. The system is complex, heavy and large, and costly. In addition, the power of the front and rear axles cannot be distributed from 0 to 100, and the front and rear torque distribution capabilities are relatively limited.

(Torsen differential structure diagram)

As one of the technology lovers in the automotive industry, Audi will not stop at the "former glory" of the Torsen differential, and it tries to find a solution. For example, the RS4 ( parameters | pictures ) in 2006 used a multi-plate clutch to distribute power to the rear wheels; another example is the 2010 sixth-generation quattro, which uses a semi-mechanical crown gear differential. Compared with the Torsen differential, it brings many benefits: lighter weight, better transmission efficiency, lower fuel consumption, and the torque ratio between the front and rear axles can be continuously changed between 70:30 and 15:85, and can also be controlled electronically.

(Structure diagram of Audi's seventh-generation quattro crown gear central differential)

It wasn't until 2016 that Audi added the word "ultra" after quattro.

What is quattro ultra?

Look it up in the dictionary first. The word “ultra” means extreme or super.

Audi has been fond of the word "ultra" since 2011, because the Le Mans prototype car of that year was called R18 TDI ultra , and Audi R18 won four consecutive Le Mans titles. Later, there were hard-core technologies and products such as ultra lightweight technology and ultra series models.

So back to quattro ultra, what does ultra bring to quattro?

Do you remember the “two philosophical questions” about four-wheel drive that you saw at the beginning?

1. When, how and in what proportion is the power distributed to the front and rear axles?

2. When, how or in what proportion is the power distributed to the left and right wheels?

(Main structure and components of quattro ultra)

Audi quattro ultra can answer these two questions very well, because it uses an electronically controlled multi-plate clutch as the central differential, finally realizing true "electronically controlled four-wheel drive" and can achieve a front and rear axle power distribution of 100 ( parameters | pictures ): 0~0:100.

Moreover, its newly added rear axle tooth coupler can completely block the power input to the rear axle.

That's right, in general, the full-time four-wheel drive system has better grip and faster acceleration, but it is relatively fuel-consuming; the part-time four-wheel drive system is just the opposite, it is more fuel-efficient, but it often has disadvantages such as slow speed from two-wheel drive to four-wheel drive and poor off-road escape ability.

However, if these shortcomings of timely four-wheel drive can be solved, for example, by being able to switch between two-wheel drive and four-wheel drive modes more accurately and quickly, while maintaining two-wheel drive when not needed, can we achieve the goal of taking advantage of others' strengths and overcoming their weaknesses?

The quattro ultra four-wheel drive is different

We have to admire the powerful computing power of artificial intelligence, which even eclipses the top Go masters. This computing power has also been applied in many fields, such as the quattro ultra.

The Audi quattro ultra's computer detects 150 different signals 100 times per second, including temperature, humidity, navigation and other data. During driving, the sensors of the four-wheel drive system monitor the condition of the entire vehicle and can detect tire slip, cornering speed, engine torque, etc. All data will be simulated by the computer at a speed of 100 times per second and predict the grip conditions in 0.5 seconds.

What does this mean? Just like big data can calculate the financial help you may need based on your consumption habits and income, the quattro ultra computer will analyze your driving operation and vehicle status, and then help you calculate the torque and grip in 0.5 seconds at the moment you turn. When it thinks that the driving force will exceed the maximum grip, the system will switch to four-wheel drive mode half the time in advance to help you drive.

It only takes 0.2 seconds to switch between two-wheel drive and four-wheel drive. You should know that the normal reaction time of a normal person is 0.2-0.4 seconds, which means that you can basically not notice the switch.

And most importantly, this will enable the four-wheel drive system to change from passively adapting to actively responding to different road conditions.

Finally, let’s talk about something more practical. Because the power to the rear axle can be cut off, the power loss can be reduced by up to 10%. The average fuel consumption per 100 kilometers is at least 0.3 liters less than the conventional quattro system. The quattro ultra system as a whole also reduces the weight by 4 kilograms through the use of lightweight materials and structural optimization.

Evolution from instinct to intelligence

Decades ago, machinery brought us convenience;

More than a decade ago, computers brought us convenience, but machines or even manual labor may still be more reliable;

In recent years, most people have been enjoying the convenience of intelligence, and reliability is no longer a problem.

As a result, the in-vehicle system has intelligent voice, driving has assisted driving and even automatic driving, and it is time for the Audi quattro, which has always been famous for its mechanical stability, to add intelligence and become quattro ultra!

The birth of new things is always accompanied by various questioning voices, but truly powerful and meaningful new technologies are changing our lives unknowingly.

The four-wheel drive system of automobiles should also follow this trend and develop from instinct to intelligence...