Power steering architecture without mechanical connection between the steering wheel and the steering mechanism of the vehicle

A method for controlling a power steering system of a motor vehicle, the method comprising:

• detecting an operating state of a steering actuator mechanically coupled to a first steering pinion engaged with a steering rack of the motor vehicle;
• when the steering actuator is operational, providing, by a first control unit of the steering actuator, a torque setpoint to a main motor of the steering actuator;
• when the steering actuator fails, but provides an angular position measurement of the main motor, controlling, by a second control unit, a brushless auxiliary motor, mechanically coupled to a second steering pinion engaged with the steering rack, using a closed-loop angle regulation function receiving the angular position measurement of the main motor and an angular position measurement of a steering wheel of the vehicle;
• and
• when the steering actuator has completely failed, controlling the auxiliary motor by the second control unit, using an open-loop angle regulation function receiving the angular position measurement of the steering wheel.