Model based fault detection of hydraulic brake system components

For active control of the vehicle's lateral and longitudinal dynamics with hydraulic brake systems, the brake pressure in the wheel brake cylinders is modulated with electro-magnetic actuators (fast switching solenoid valves). A malfunction of these, e.g. a blocked armature (the armature does not move in spite of electrical excitation), may lead to highly dangerous driving situations. To increase driving safety such a malfunction in a car should be detectable. Presently the valves mechanical functionality can only be tested in workshops with special technical equipment and with increased effort. This paper shows how the armature movement of the magnetic valve, respectively its switching functionality, can be reconstructed, exploiting the valve's mechatronic properties. For this, only the signals armature current and voltage need to be measured.