USE OF A SERVO MOTOR OF A POWER STEERING SYSTEM TO GENERATE TEST CYCLES ACCORDING TO A SPEED ASCERTAINING CYCLE

A power steering system having at least one steering wheel, steering mechanism provided with rack, and at least one servo motor, the method having, outside steering phase during which power steering system is assigned to driving of vehicle to cause vehicle to follow trajectory which is determined as function of the situation of vehicle with respect to its environment, step (a) of automatically activating the servo motor, during which step computer is used to automatically generate and apply the servo motor, without requiring any external action on steering wheel, activation instruction that follows one or more cycles referred to as pre-established exploration cycles in order to measure, during at least one exploration cycle or at the end of at least one exploration cycle, at least one indicator parameter which is specific to response by power steering system to automatic activation of servo motor and which is characteristic of desired property.