SECURING THE ASSISTANCE TORQUE BY MEANS OF AN ESTIMATOR OF THE FORCE ON THE RACK

摘要

The invention relates to a method for securing the assistance torque (15) supplied by an electric assistance motor (8) in a motor vehicle power steering system, the securing method being characterized in that it includes the steps of: estimating the force on the steering system rack from the torque exerted by the driver on the steering wheel (2), from the assistance torque (15), and optionally from other parameters such as the speed of the electric assistance motor; comparing a target assistance torque with an authorized assistance range, defined with respect to the estimated rack force (17) at any moment, and in the event the target assistance torque is maintained above predefined limits for a predefined duration, correcting and optionally interrupting the power steering.