Electrically operated braking system having a device for operating electric motor of brake to obtain relationship between motor power and braking torque

摘要

An electrically operated braking system of a motor vehicle, including a brake having a friction member movable to be forced onto a rotor rotating with a vehicle wheel and thereby braking the wheel. The friction member is forced onto the rotor by an electric motor operated by an electric power supplied from an electric power source. A controller determines an amount of the electric power to be supplied to the motor, depending upon an operating amount of the brake operating member, and a relationship estimated by a relationship estimating and utilizing device. The relationship estimating and utilizing device obtains an actual value of the electric power supplied to the motor during operation of the brake while the vehicle is running, and an actual value of a braking torque applied from the brake to the wheel during the brake operation, and estimate a relationship between the electric power to be supplied to the wheel on the basis of the actual values obtained. The estimated relationship is then utilized to control the braking torque to be generated in response to operation of the brake operating member.