Vehicle brake system having adaptive torque control

A vehicle brake system comprising:

• a brake demand input;
• a sensor for determining kinematic acceleration of a vehicle;
• a frictional brake actuator for generating friction braking to be applied to one or more brakes on the vehicle;
• a regenerative brake actuator for providing regenerative braking of the vehicle;
• a database storing target accelerations as a function of the brake demand input, a brake related parameter that defines a relationship between the brake demand input and the friction braking, and brake data from previous vehicle braking events;
• and
• a controller for controlling the friction brake actuator and regenerative brake actuator, said controller determining a brake acceleration caused by the friction braking as a function of the kinematic acceleration and determining a target acceleration from the database based on the brake demand input, said controller further determining a brake acceleration error as a difference between the target acceleration and the brake acceleration, said controller further adjusting the brake related parameter to reduce the brake acceleration error by adjusting the braking generated by the friction brake actuator to compensate for brake feel variation.

A method of controlling a brake system to compensate for brake feel variation, said method comprising the steps of:

• receiving a brake demand input signal indicative of braking demand requested by an operator of a vehicle;
• determining kinematic acceleration of the vehicle;
• determining brake acceleration caused by the braking as a function of the kinematic acceleration;
• determining a target acceleration from stored data based on the brake demand input;
• determining a brake acceleration error as the difference between the target acceleration and the brake acceleration;
• generating braking to be applied to one or more friction brakes on the vehicle as a function of a brake related parameter, wherein the brake related parameter defines a relationship between the brake demand input and the friction braking;
• and
• adjusting the brake related parameter to reduce the brake acceleration error by adjusting the braking generated by the friction brake actuator so as to compensate for brake feel variation.