A study is presented dealing with the synergism coming from the integration of such controlled systems which are designed for improving the dynamic behaviour of road vehicles. A modified 1/4 car model is derived which allows suspension, torque and steering control to be applied to a low order vehicle model. A number of investigations, based either on complex vehicle models or on ground tests, show that important synergistic effects can be obtained from the integration of suspension, torque and steering controls. The straight running on irregular roads may take advantage from the co-operation of active suspension and four-wheel-steering systems. The braking under split conditions can be improved with a proper control of ABS and rear wheel steering. The driveability of a car entering a curve with changing surface conditions could be substantially enhanced thanks to the combined exploitation of ABS and additional four wheel steering. (A)
Abstract