Patent ID: 6019441
Filing Date: 2000-02-01
Classification: B60T

Abstract:
A method of operation for an automotive anti-lock braking system in which an electrically controlled solenoid valve in a hydraulic line coupling a master cylinder to a braking device is electrically activated to a first position to permit unimpeded fluid flow in said hydraulic line or a second position to interrupt fluid flow in said hydraulic line, the method comprising the steps of:energizing the solenoid to move the valve to the second position to interrupt fluid flow in said hydraulic line;de-energizing the solenoid for a first interval that allows its current to decay to a scheduled value for moving the valve to a desired position intermediate said first and second positions;maintaining the solenoid current at said scheduled value for a second interval to maintain said valve at said desired position;re-energizing said solenoid for a third interval that allows the solenoid current to return to a steady state value, thereby substantially returning said valve to said second position; andrepeating said de-energizing, maintaining, and re-energizing steps with successively lower scheduled current values to gradually re-establish unimpeded fluid flow in said hydraulic line.