Method for improving the controllabilty of motor vehicles

Method for improving the controllability of a wheeled vehicle during braking of wheels of the vehicle, comprising the steps of:

• measuring yawing speed .psi., wheel speeds V.sub.Ri, steering angle .delta. and at least one of inlet pressure P.sub.inlet and wheel brake cylinder pressures P.sub.i, where i represents a respective wheel and equals 1, 2, 3 or 4;
• supplying these measured variables .psi., V.sub.Ri, .delta., and at least one of P.sub.inlet and wheel brake pressures P.sub.i to a slip controller and, from these measured variables, determining longitudinal vehicle speed V.sub.X, longitudinal vehicle acceleration V.sub.X, respective wheel slip values .lambda..sub.i, and braking forces F.sub.Bi ;
• supplying the determined variables F.sub.Bi, .lambda..sub.i and V.sub.X to an observer which, with the aid of the measured variables .lambda. and .delta., determines tire forces F.sub.Ri and a vehicle transverse speed V.sub.Y from these variables;
• supplying the determined variables V.sub.X, V.sub.X, .lambda..sub.i, F.sub.Ri and V.sub.Y and the measured variables .psi. and .delta. to a vehicle controller;
• in the vehicle controller, and with the aid of a simple vehicle model and the determined and measured variables supplied to the vehicle controller, determining desired slip values .lambda..sub.i.sup.* that effect a better controllability of the vehicle for the respective wheels;
• supplying the desired slip values .lambda..sub.i.sup.* to the slip controller;
• and
• via the slip controller, controlling the respective wheel brake cylinder pressures P.sub.i at the wheel brakes to achieve the desired slip values .lambda..sub.i.sup.* at the respective wheels.