System for determining side slip angle

In a yaw moment control system for improving the driving behavior of an automotive vehicle tending to oversteering or understeering, the vehicle having means for determining a reference velocity value and a plurality of sensors for generating signals representing lateral acceleration of the vehicle, a steering angle of the vehicle and a measured yaw rate of the vehicle, apparatus for generating an estimated velocity of the side slip angle of the vehicle, comprising:

• observer model means for generating a value representing an observer model velocity of the side slip angle and a yaw acceleration rate value based on the reference velocity value, the signal representing the steering angle, an estimated side slip angle value and a feedback signal;
• means for forming the feedback signal based on the yaw acceleration rate value and the signal representing the measured yaw rate;
• kinematic determination means for generating the estimated velocity of the side slip angle based on the reference velocity value, the estimated side slip angle value, and the signals representing the lateral acceleration and the measured yaw rate;
• and
• means for forming the estimated side slip angle value based on the values of the observer model velocity of the side slip angle and the estimated velocity of the side slip angle.