Patent ID: 6499813
Filing Date: 2002-12-31
Classification: B60T,F04B

Abstract:
A method for driving a pump motor of a brake system, having a superordinate control logic and a supply voltage that is switchable across the pump motor, comprising:receiving at least one braking request signal from the superordinate control logic; switching on the supply voltage for an initial full drive period; cycling the supply voltage, following the initial full drive period, for so long as the at least one braking request signal remains active, wherein the step of cycling has a drive cycle period, and the step of cycling comprises: switching off the supply voltage for an interpulse period; measuring a regeneratively induced pump motor voltage; comparing the regeneratively induced pump motor voltage to at least one threshold voltage; switching on the supply voltage for the remainder of the drive cycle period, if the regeneratively induced pump motor voltage drops below the at least one threshold voltage; switching on the supply voltage for a minimum pump on-time, if the regeneratively induced pump motor voltage remains greater than or equal to at least one threshold voltage for a maximum pump off-time; interrupting the step of cycling, if the regeneratively induced pump motor voltage drops below a threshold safety voltage; switching on the supply voltage for a period of time that is not necessarily the same as the drive cycle period; and resuming the step of cycling.