Abstract: To set the brake or traction slip of a wheel at the maximum of the frictional value/slip curve, it is necessary that the wheel sensor associated with each wheel to sense its rotational speed is in a state of operation. Otherwise it is not possible to ascertain the slip of the respective wheel. In order to ensure an emergency function for influencing driving dynamics parameters even in the event of malfunction of a wheel sensor, the present invention discloses performing a two-point control when a wheel sensor is defective. A first operating point (A) lies at a longitudinal slip equal to zero, and a second operating point (B) lies at a longitudinal slip of 100%. Without a longitudinal slip, lateral forces can be transmitted to their maximum, whereas at 100% longitudinal slip longitudinal forces can still be transmitted almost to their maximum.

Abstract: Method of Determining a Vehicle Deceleration or Acceleration A method which permits determining a vehicle deceleration or acceleration from the signals of the wheel sensors. The method includes two different types of calculation which take into consideration that the vehicle is temporarily in a slip control operation during which the single wheel speeds per se are not representative of the vehicle speed. If some of the wheels are not subjected to slip control, these wheels may be taken into account for determining the vehicle deceleration or acceleration. If, however, all the wheels undergo a slip control operation, a maximum amount gradient is respectively determined from the speed variation of non-driven wheels which comes closest to the vehicle deceleration.

Abstract: A circuit arrangement which is provided for a vehicle with an electronic anti-lock control system and is used to enhance the driving stability in critical driving situations includes circuits for the individual control of the braking pressure on the front wheels and for limiting the yawing torque following braking maneuvers on .mu.-split road surfaces. In defined, especially critical driving situations, in particular during driving maneuvers with an abrupt change in .mu.-conditions or during braking maneuvers on .mu.-patch road surfaces, when predetermined criteria for a critical driving situation of this type are satisfied, a special control is started to bring about braking pressure reduction on the HM-wheel for a predetermined period which is responsive to vehicle speed.