Patent ID: 8527176

Claim:
A method for measuring pressure, without requiring use of pressure sensors, in a pressure regulation unit of a motor vehicle braking system having a motor pump unit composed of an electric motor and a hydraulic pump, wherein the motor is actuated by means of electrical pulse width modulation, comprising the steps of: producing a relative motor characteristic diagram for a series of the pressure regulation unit or of the motor pump unit or of the motor before the manufacture of an individual of the pressure regulation unit or of the motor pump unit or of the motor which diagram includes at least the data of motor-rotational-speed-dependent parameters (n/n 0 ), and intensity of the motor actuation (DC), and parameters relating to the level of the motor load (P_G), determining individual motor characteristic variables (N_MAX, N_ 200 , U 2 N) after or during the fabrication of the motor pump unit or of the motor, determining a current rotational-speed-dependent parameter of an individual motor (N act ) during the operation of the pump, and calculating a pressure (P THZ ), which is characteristic of the braking system, by means of the motor characteristic diagram and the motor-rotational-speed-dependent parameter of the individual motor (n act ) and the value of the current motor actuation (DC) which determines the intensity of the motor actuation, wherein the individual motor characteristic variables are taken into account.