After having established itself in the top-of-the-range vehicles, the electronic suspension will probably conquer the mid-range-, and more than likely, the transporter sectors as well. As far as safety, comfort and above all, the braking are concerned, the possible advantages are far too attractive to be ignored.
Just imagine, you're driving home, e.g., after a hard days work, with a pretty comfortable suspension. You and your car hardly notice the wavy or patchy road surface. The advantage of today's modern systems is, when a dangerous situation e.g., like having to swerve occurs, the suspension is hardened in a split second, giving one the impression of having had a sports suspension installed.
The further advantages won't be comprehensively mentioned. Just think, how valuable a level-control system could be, e.g., for the headlamp height adjustment or for transporters whose level changes when loading and unloading. This can also apply when the loading level is zero, e.g. when transporting wheel-chair passengers. Almost more important is the possibility of the cooperation between the brakes and the suspension, which could result in a further shortening of the braking distance.
As we said, there's no telling what possible advantages could be achieved. There are groups of researchers, who are improving the feeling of the passengers when cornering. The inside- and the outside mounted springs are so differently controlled, that if one was blindfolded, one would have the feeling of travelling in a straight line. In particularly high performance models e.g., there is the concern that when accelerating, the rear end dips too much. Instead of complicated steering control, in the future, one could have assistance from the electronc air suspension.
Before we go on to the subject of the components, it must be mentioned that basically, compared with a conventional suspension, the exchanging of components is more simple. Due to the fact that here, suspension struts are often also used, there is only really one problem, the springs and the shock absorbers must be separately mounted, e.g., when the wheel-housings are to be kept as narrow as possible, to allow the widest possible boot space.
For the construction of an electronically regulated air suspension, one needs, first of all, a pressure- production and storage system. Thereby, the positioning of the compressed air tank may cause some problems. Similar to the ABS-system, the valve block which activates the control device, is mounted directly onto the compressor. Of course this also needs sensors, e.g., for the build-up acceleration, the spring-travel and for the pressures. All that's missing now, are the four air-struts, best of all, with integrated damper control.
Now the control device can take over. How much influence the driver actually has, will probably depend on the manufacturer. At any rate, the level will be modifiable, from the lowest setting for high speeds, to the highest, for off-road use or, if it still takes place, the changing of a wheel. Of course, this is all independent of the amount of load being carried, thereby, the springing can still be somewhat more comfortable than with progressive steel springs. Into the bargain, the comfort of the damper regulation can also be reduced in a critical situation.
One has already started to examine the various parameter changes when braking takes place. Even though the 35 meters needed nowadays, to brake from 100 kmh down to zero in a mid-range car are not bad at all, the people at Continental are promising as little as 30 meters, if all the change values are kept under control. This includes, apart from the center of gravity, also the front-end setting measurements for the suspension and e.g., the positive influencing of the yaw-behaviour. Just as with ABS, the steering and the brakes are networked, in the future so will the chassis and the brakes be, according to the motto, “sometimes less is more”.
When considering the above mentioned components, you may ask yourself, why modern systems still need a pressure storage tank. Should air be necessary, the compressor can supply it and bleeding off air poses no problem at all. Indeed, perhaps it does, 16 bar of pressure is not chicken-feed, at least not in terms of energy production. Thus, the pressure tank, where only the pressure differences have to be taken care of, once again comes into play. 11/11