Brake control system

In a vehicle with an active brake control system (52, 54, 56, 58, 68) and a plurality of vehicle wheels (12, 14, 16, 18), wherein the active brake control system has an active state and an inactive state for each wheel, a control method comprising the steps of:

• determining individual wheel speeds of the vehicle wheels responsive to sensor output signals (1016, 1018);
• determining a vehicle reference velocity responsive to the individual wheel speeds (1002-1012);
• measuring vehicle yaw rate (1128);
• determining a delta velocity for each wheel responsive to the individual wheel speed for the wheel and the vehicle reference velocity (326);
• and
• when the active brake control system is in the active state for at least one of the wheels,
• (a) setting a base delta velocity for the at least one of the wheels equal to the delta velocity for the at least one of the wheels immediately prior to the active brake control obtaining the active state for the at least one of the wheels (200);
• (b) determining a control term responsive to the measured vehicle yaw rate (806), wherein the control term represents a desired delta velocity for the at least one of the wheels;
• (c) setting a first target change in delta velocity responsive to the base delta velocity and the control term (204), wherein the first target change in delta velocity represents an amount of change desired in the delta velocity for the at least one of the wheels;
• and
• (d) controlling a first wheel brake for the at least one of the wheels so that a difference between the delta velocity for the at least one of the wheels and the desired delta velocity for the at least one of the wheels is minimized (208).