Patent ID: 8630771

Claim:
A control method for a steering system with electric power assistance, the steering system including a steering wheel, controllable by a driver, an electric power assist motor, an electric control unit, which includes a memory for storing digital data, a motor controller that, based on a target engine torque sent to the motor controller, determines and sends out electrical signals for controlling the electric power assist motor, at least one sensor device for determining a control variable introduced into the steering wheel, a damping element for generating a damping signal, and a stabilisation element for generating a stabilisation signal, and the method comprising: determining in the control unit, with the help of the control variable, a preset value for an engine torque of the electric power assist motor; using an upper threshold value for target engine torque stored in a limiting element; for a case A, in which the preset value exceeds the upper threshold value, delivering, by the limiting element, the upper threshold value as the target engine torque to the motor controller; for a case B, in which the preset value does not exceed the upper threshold value, delivering, by the limiting element, the preset value as the target engine torque to the motor controller; a safety function performing a redundant calculation of the output signals of the limiting element, of the damping element and of the stabilisation element; and summing output signals of the limiting element, the damping element and the stabilisation element, and outputting a result of said summing to the motor controller as the target engine torque.