Variable control-gearing ratio electrical steering system i.e. steer-by-wire steering system, controlling method for motor vehicle, involves determining setpoints of steering rack position and effort of variable reduction system actuator

摘要

The method involves measuring speed of a vehicle, a steering wheel angle, a steering rack position (Xcrem) and effort on left and right tie rods (3a, 3b) between steering racks (4) and front left and front right spindle carriers (2a, 2b). The steering rack effort is determined, where the rack effort is equal to a difference between the efforts on the tie rods. Setpoints of a steering rack position and an effort of a variable reduction system actuator e.g. plotter actuator (15) such as synchronous electrical motor, are determined based on the steering wheel angle and the steering rack effort. An independent claim is also included for a device for controlling a variable control-gearing ratio electrical steering system of a vehicle.