Detection method of a steering reversal by monitoring of the torque provided by a steering assist motor and application of said method for evaluating the friction

摘要

A method for managing a power steering system, including a step (a) of detecting a reversal in the steering direction which involves acquiring a signal, referred to as a “motor torque signal” (C_Mot), representative of the assistance force (C_assist) delivered by the power steering motor, then evaluating the time derivative (δC_Mot/δt) of the motor torque signal, then comparing the time derivative of the motor torque signal to a predefined variation threshold (S_pic) in order to detect a derivative peak, greater than the variation threshold (S_pic), that indicates a reversal in the steering direction. The method next includes a friction evaluation step (b) which involves evaluating the friction from the drop, during the reversal in the steering direction, in a so-called “actuation force signal” (C_action), which is representative of the total actuation force exerted together on the power steering by the driver and by the power steering motor.