In the past there was a development of stability control systems for front- and rear-wheel driven cars. These systems will come to the market under the names ASR, ETC or ASC. Completely independent of these systems, four-wheel driven cars were developed. They have, specially with locked differentials, maximum traction.
In this paper we are combining four-wheel driven cars with the systems for stability control. We made some research, in what way the independent systems add to each other, optimize the driving behaviour of the vehicle.
These works were done with comprehensive computer-simulation and with experiments on real cars. It will be shown, that the combination of the systems will be possible, if we will get a reference for the wheel velocities. Possibilities for solving this problem are additional sensors or the use of the vehicle dynamics theory in the real cars.
As a result, control systems are developed, which will help the drivers in critical driving situations. Thus it is a contribution to Active Safety. The future usage of the system in cars for series production will depend on the ability to realize them for acceptable cost.