BLENDED VEHICLE BRAKE SYSTEMS AND CONTROL LOGIC WITH FRICTION BRAKE BURNISH LEARNING AND COMPENSATION

A blended brake system includes a regenerative (regen) brake system and a friction brake system that cooperatively decelerate a motor vehicle. A method of operating the blended brake system includes a vehicle controller receiving a brake command with a corresponding brake torque request. From this brake torque request, the controller determines a regen brake torque for the regen brake system and a friction brake torque for the friction brake system. The controller uses the friction brake torque and an estimated temperature of a rotating friction brake element to determine a temperature-dependent friction coefficient, and uses the friction brake torque and an estimated burnish state of the friction brake system to determine a burnish-dependent friction coefficient. A modified friction brake torque is calculated from a modified brake pressure coefficient derived from the temperature-dependent and burnish-dependent friction coefficients. The friction brake system applies the modified friction brake torque to slow/stop the vehicle.