Patent ID: 6820715
Filing Date: 2004-11-23
Classification: B62D,H02K

Abstract:
An electrical steering system for a vehicle, comprising:at least one steerable wheel capable of being steered; operating means for effecting a change of direction, which deliver three electrical signals that all carry the same information about the required change of direction; for each of the steerable wheels, an electrical actuator for altering the steering angle of the steerable wheel, the electrical actuator comprising a reference end and a control end which is displacable with respect to the reference end, the electrical actuator being suitably connected to the steerable wheel, the actuator having three electric motors which act in parallel in order to displace the control end with respect to the reference end; for each electrical actuator, three position sensors for sensing the relative position of the control end with respect to the reference end; three controllers which operate in parallel, each forming part of an electrical control channel for the steering angle, the controller of each electrical channel receiving one of the three electrical signals and being connected to one of the position sensors and driving one of the electric motors in order to set the steering angle, the torque delivered by each of the motors being added together in normal operation; at least one interconnection bus for the three electrical control channels; and means for detecting a discrepancy in the status of one electrical channel with respect to the other two, in order to change to operation in a downgraded mode in the event of a discrepancy.