Method for controlling yaw and transversal dynamics in a road vehicle

Abstract

For the purpose of controlling the yaw dynamics and lateral dynamics in a road vehicle with electrically controlled four-wheel steering, in the case of which the setting of the front axle steer angle δand of the rear axle steer angle δis performed by means of mutually decoupled control loops, a desired value δfor the lateral force Sto be built up at the front axle is determined in the control loop assigned to the front axle and, for this desired value S, the value of the slip angle, linked to the desired value S, is determined as desired value αfrom an S(α) characteristic representing the dependence of the lateral force S, to be built up at the front axle, on the slip angle α. In the control loop assigned to the rear axle, a desired value Sfor the lateral force Sto be built up at the rear axle is determined in a control process in accordance with a controller law of the formand, for this desired value S, the value of the slip angle, linked to the desired value S, is determined as desired value αfrom an S(α) characteristic. These desired values αand αare used to determine the desired values δand δof the steer angle, taking account of an estimated value of the sideslip angle β at the center of gravity of the vehicle, the position of the center of gravity and measured or estimated values of the yaw velocity {dot over (Ψ)} and of the longitudinal speed vof the vehicle.