Vehicle Steering Control Without Mechanical Connection Between the Steering Wheel and the Steered Wheels

Abstract

Steering control system with variable ratio, comprising a control member (2) available to a driver to act on the vehicle steering, the said control member being able to be manoeuvred within a maximum range (θmax) between a stop to the left and a stop to the right and delivering a requested steering signal (θ) quantified in terms of amplitude and direction, the said steering system comprising at least one actuator (3) for acting on the steering angle of the at least one steered wheel, the said steering system comprising a controller (4) using as input variables at least the speed of the vehicle (V) and the said requested steering signal (θ) in order to determine, for each of the actuators, a control angle (α) according to which the actuator is controlled for the steering, comprising a first unit (41) for determining, at least according to the speed of the vehicle (V) and preferably according to the maximum transverse acceleration (γy max) of the vehicle, a maximum steering (βmax) on the single steered wheel on an equivalent bicycle model of the vehicle, a second unit (42) for determining a gearing-down ratio (RD) according to the said maximum range (θmax) of the control member and the said maximum steering angle (βmax), a final unit (43) for determining the said steering angle or angles (α) according to the said gearing-down ratio (RD) and the said requested steering signal (θ).

Dependencies are inferred from the claim text.