Electronic parking brake EPB system and method of controlling the same

1. An electronic parking brake (EPB) system including an EPB actuator operated by a motor, the EPB system comprising:

a motor driver which drives the motor of the EPB actuator;

a current detector which detects a current flowing in the motor; and

an electronic control unit (ECU) which drives the motor using the motor driver according to an operation mode, calculates an amount of current energy consumed by the motor using the current detected by the current detector while the motor is driving and a detecting time taken to detect the current, compares the calculated amount of current energy and a preset value, and controls an operation of the motor according to a result of the comparison,

wherein the operation mode includes a parking operation mode, a parking release mode and a pad exchange mode, and the preset value is set differently depending on the operation mode.

2. The EPB system of claim 1 , wherein the ECU calculates a voltage difference between both terminals of the motor and calculates an amount of current energy consumed by the motor while the motor is being driven based on the calculated voltage difference and an internal resistance of the motor.

3. The EPB system of claim 2 , wherein when the calculated amount of current energy is greater than the preset value, the ECU determines that the motor is overloaded.

4. The EPB system of claim 3 , further comprising a warning portion which warns of the overloading of the motor,

wherein when the ECU determines that the motor is overloaded, the ECU stops an operation of the motor using the motor driver and warns of the overloading of the motor using the warning portion.

5. The EPB system of claim 1 , wherein when the calculated amount of current energy is greater than the preset value, the ECU determines that the motor is overloaded.

6. The EPB system of claim 5 , further comprising a warning portion which warns of the overloading of the motor,

wherein when the ECU determines that the motor is overloaded, the ECU stops an operation of the motor using the motor driver and warns of the overloading of the motor using the warning portion.

7. The EPB system of claim 1 , further comprising:

a memory which stores the motor current flowing in the motor; and

a counter which counts time while the motor is driving,

wherein the ECU stores each of the current detected by the current detector while the motor is being driven and the detecting time taken to detect the current in the memory, calculates an amount of current energy consumed by the motor since start of a corresponding operation mode to a present point using the current and the detecting time stored in the memory, compares the calculated amount of current energy and a preset value, and determines whether the motor is overloaded.

8. The EPB system of claim 1 , wherein when the ECU calculates the amount of current energy, the ECU calculates at least one of a first amount of current energy which is a cumulated value of a product of the motor current (I) and the detecting time (t) stored in the memory while the motor is being driven or a second amount of current energy which is a cumulated value of a product of a square of the motor current (I) and the detecting time.

9. The EPB system of claim 8 , wherein when at least one of the first amount of current energy and the second amount of current energy is greater than a value preset to correspond to a current operation mode, the ECU determines that the motor is overloaded.

10. The EPB system of claim 1 , wherein the parking operation mode is configured to provide braking power to disc brakes and the parking release mode is configured to release the braking power provided to the disc brakes.

11. The EPB system of claim 1 , wherein the pad exchange mode is configured to rotate the motor of the EPB actuator in a direction opposite to a direction of a parking operation.

12. A method of controlling an EPB system including an EPB actuator operated by a motor, the method comprising:

driving the motor according to an operation mode;

detecting a current flowing in the motor while the motor is being driven and a detecting time taken to detect the current;

storing the detected current and the detecting time;

calculating an amount of current energy consumed by the motor since start of a corresponding operation mode to a present point using the stored current and detecting time; and

comparing the calculated amount of current energy and a preset value and determining whether the motor is overloaded,

wherein the operation mode includes a parking operation mode, a parking release mode and a pad exchange mode, and the preset value is set differently depending on the operation mode.

13. The method of claim 12 , wherein the calculation of the amount of current energy includes calculating at least one of a first amount of current energy which is a cumulative value of a product of the motor current (I) and the detecting time (t) stored in a memory while the motor is being driven or a second amount of current energy which is a cumulative value of a product of a square of the motor current (I) and the detecting time.

14. The method of claim 13 , wherein the determining of whether the motor is overloaded includes determining the overloading of the motor when at least one of the first amount of current energy and the second amount of current energy is greater than a value preset corresponding to a current operation mode.

15. The method of claim 12 , wherein the parking operation mode is configured to provide braking power to disc brakes and the parking release mode is configured to release the braking power provided to the disc brakes.

16. The method of claim 12 , wherein the pad exchange mode is configured to rotate the motor of the EPB actuator in a direction opposite to a direction of a parking operation.