Calibration method for friction pad and electro-mechanical brake apparatus using the same

A method of calibrating for a parameter variably changed according to wearing out or thermal deformation of a friction pad mounted on an electro-mechanical brake (EMB) of a vehicle, during driving, using a main controller, the method comprising:

• determining whether it is necessary to calibrate the parameter;
• in response to (1) determining that it is necessary to calibrate the parameter or (2) receiving, from an EMB controller, a calibration request signal, determining whether a state of the vehicle is a non-braking state and a non-accelerating state;
• and
• in response to determining that the state of the vehicle is the non-braking state and the non-accelerating state, generating and transmitting, to the EMB, a calibration start command instructing to start calibrating the parameter,
• wherein the main controller, when the EMB receives a braking signal or an acceleration signal for the vehicle while the EMB is calibrating the parameter in response to receiving the calibration start command, generates a calibration stop command and transmits the calibration stop command to the EMB.

An apparatus for calibrating a parameter variably changed according to wearing out or thermal deformation of a friction pad while a vehicle is driving, the apparatus comprising:

• an electro-mechanical brake (EMB) configured to brake the vehicle;
• and
• a main controller configured to:
• generate (1) a calibration start command instructing the EMB to start calibrating the parameter or (2) a calibration stop command instructing the EMB to stop calibrating the parameter;
• and
• transmit the calibration start command and the calibration stop command to the EMB,
• wherein the calibration start command includes:
• a torque blending command instructing to (1) reduce a regenerative braking force of the EMB and (2) generate a friction braking force corresponding to the reduced regenerative braking force;
• a contact point measurement command instructing to measure a contact point using a motor rotation angle sensor and a current sensor;
• and
• an error correction command instructing to compare a first contact point previously stored and a second contact point measured after the first contact point was measured and to remove an error between the first and second contact points, and wherein the calibration stop command includes:
• a first stop command instructing to stop calibrating the parameter when the EMB is calibrating the parameter in response to receiving the calibration start command from the main controller;
• and
• a second stop command instructing to continue to stop calibrating the parameter when the EMB is not calibrating the parameter in response to not receiving the calibration start command from the main controller.