(It adapts as if it knows)
Life is bumpy by nature, it’s 70% oceans and the rest is driving heaven; rocky, green, white and tarmac fields created to be driven across! Just look around you and you see 1000 Miglia, Targa Florio, Paris-Dakar and many other fields of our heaven where small angels, we like to call “drivers”, fly from a place to another in machines that compromise between grip, ride quality and speed.
Given the bumpy nature of the place, an invention called suspension was put to the use. Just like our fellow artistic engineers, the architects use, for bridges and huge towers, suspension systems to control the forced, catastrophic motion caused by the elements, we as mechanical engineers had come up with two brilliant inventions to counter the effect of the wind, gravity and surface profiles.
The first is the “suspension”. I guess when such word was created it seemed very dynamic and smart to the ears. Imagine sitting in a box with 4 wheels and your mate is dragging you over a rough surface, even the thought of this is annoying right? Now imagine how lovely it would be if this box has between it and its wheels springs and dampers, or as we call nowadays a suspension system (primitive of course), your life would be much easier along with your ride, don’t you think?
The second invention is the “active suspension”! Thank god man was slightly smarter and a little bit more demanding to realize that springs and dampers are too passive and fully controlled by the outer conditions. Truly suspension is a compromise between of the ride’s quality, its speed and the grip you have with the surface you are traveling on. So the suspension had to be improved, it had to be mad smart and adaptive. It might seem a tough issue for us, but not for 1981 lotus engineers who came up with the brilliant idea of making a smart suspension system or active suspension that respond to the road in a way to keep grip to the vehicle and comfort to the driver.
Today’s suspension can control numerous parameters, including the high of the center of gravity and the momentum of the car. We can differentiate between active and semi active: where the first is known to use separate actuators which can exert an independent force on the suspension to improve the riding characteristics. The second can only change the viscous damping coefficient of the shock absorber; meaning making the absorbers more/less stiff or counteractive. All this to keep your tires perpendicular to the road’s corner in order to secure a high level of grip and comfort.
Mercedes-Benz summarized everything I just said in something they called ABC (active body control), also they introduced what they called the Airmatic system, like on W220 or W221 (S-class). But If you compare a car with Airmatic to a car with ABC you would notice how savage and strong is the second’s response to the outer environment, working 193 bars of pressure. Also the SL-model is notorious by its ABC which makes the car one of the most comfortable roadsters ever made. But this model somehow loses its charm when you buy it second hand given that after a while of usage ABC start to malfunction and the diagnosis of this system is very complex.
Range Rover, on the other hand, brags about its suspension system, which the manufacturer consider as a vital heritage and say that it’s what make rover the most flamboyant off-road machine, that’s what “they” say. However there suspension system is quite adaptive and consist of a communication link between ECU and a 10L reservoir of air as in the classic 4.0L and 4.6L models. And what is funny is that their diagnosis of the errors that might occur with this system is divided between what they call “fatal” and “non fatal” errors. The second type of error may most likely be a communication or linkage problem with the ECU. And I guess I don’t need to explain to you what might be the fatal error.
Finally, BMW that claim that their active suspension systems accept no compromise, you don’t believe me check it on their website. And not also that they aim for everything I stated before like comfort and grip but also noise reduction as well with their VDC or Dynamic Damper Control. But I doubt that they succeeded at least with the X6 model!
