Automatic control of vehicle motion systems has a great influence on enhanced safety. The purpose of presented analysis is to present the possibility of improving vehicle performances by using automatic devices fitted to a vehicle. This paper presents the results of investigations of intelligent control of braking, steering, suspension and power transmission systems of a vehicle, which is equipped with an antilocking braking device (ABS) and traction control one (TCS), active suspension (AS) and four wheel steering (4WS). The dynamics of vehicle was analysed in different road conditions. The solution of equations describing mathematical models was achieved numerically. Its correctness was checked by the comparison of the results of calculation with these ones obtained from the road tests.

The algorithms of the control of all devices are proposed and realised by means of the fuzzy logic method. It outlines the process used to create fuzzy sets and the rules that define the fuzzy controller. The results of the simulation outline enhancement of vehicle performances while using electronic control systems