Abstract: In a method for controlling an electric pump drive motor of a power steering device, a high output stage and a low output stage are provided, in which the motor can be operated. Between the two output stages at least one further middle output stage in which the motor can be operated is provided. A switchover between the three output stages takes place as a function of the current consumption of the motor.

Abstract: In a method for controlling an electric pump drive motor of a power steering device, a high output stage and a low output stage are provided, in which the motor can be operated. A switchover between the two output stages takes place as a function of the current consumption of the motor. Between the two output stages at least one further, middle output stage is provided, which can be switched into as a function of the current consumption of the motor.

Abstract: The object of the present invention is to provide a method for limiting the hydraulic maximum pressure of a power-assisted steering system, which permits effective pressure limitation and thus protects the individual elements of the power-assisted steering system, i.e., a pressure limitation not far above the desired maximum operating pressure, but on the other hand does not require an overdimensioning of the individual segments of the power-assisted steering system.

Abstract: To improve a method for controlling the valve characteristic in electrohydraulic power-assisted steering systems of motor vehicles so as to prevent any impairment of the steering precision, the invention proposes to control the speed of the electric motor as a function of the current consumption such that the actual current consumption and the actual speed of the electric motor are continuously measured up to a maximum speed and compared with values for the setpoint speed at the respective value of the current consumption stored in a memory and in case of deviation a correction to the setpoint speed is effected.

Abstract: A power-assisted steering system for a vehicle comprising a hydraulic motor (1) for providing vehicle steering assistance, an open center servo-valve (6) for supplying the hydraulic motor (1) with hydraulic fluid, a hydraulic pump (7) for supplying hydraulic fluid to the servo-valve (6) and to the hydraulic motor (1), and an electric motor (13) for driving the hydraulic pump (7). The hydraulic pump (7) is controlled by controlling electrical power consumed by the electric motor (13). At least one sensor (15) repetitively monitors at least one operating parameter of the power-assisted steering system. At least one microprocessor (17) repetitively calculates reference values that vary as a function of a monitored level of the at least one operating parameter.