Hybrid electric vehicle and driving control method therefor

1 . A method for controlling a hybrid electric vehicle comprising a step-variable transmission, the method comprising:

prohibiting shifting based on determining that a preconfigured deceleration braking condition is satisfied; and

slip-controlling an engine clutch disposed between an engine and a driving motor based on determining that an acceleration pedal is operated before a car stop holding time while the shifting is prohibited, in which the preconfigured deceleration braking condition is maintained, exceeds a preconfigured reference time,

wherein the preconfigured deceleration braking condition is satisfied when a brake pedal is operated, a car speed is lower than a first car speed, and a braking torque is larger than a first torque, and

wherein the car stop holding time includes a time during which the car speed is maintained lower than the first car speed and the braking torque is maintained higher than the first torque.

2 . The method of claim 1 , further comprising:

performing shifting to a first stage based on determining that the car stop holding time exceeds the preconfigured reference time without the acceleration pedal being operated.

3 . The method of claim 1 ,

wherein the slip-controlling includes outputting torque from i) the engine, ii) a starter/generator motor connected to the engine, and iii) the driving motor.

4 . The method of claim 3 ,

wherein the engine and the starter/generator motor are directly connected to each other.

5 . The method of claim 1 , further comprising:

raising a creep torque of a current shifting stage, based on a wheel torque output by a creep torque set for a first stage of the step-variable transmission, before the car stop holding time exceeds the preconfigured reference time.

6 . The method of claim 5 , further comprising:

comparing a braking torque with a preconfigured second torque based on determining that the acceleration pedal is not operated before the car stop holding time exceeds the preconfigured reference time.

7 . The method of claim 6 , further comprising:

restoring the raised creep torque when based on determining that the braking torque is equal to or larger than the preconfigured second torque as a result of the comparison.

8 . The method of claim 1 ,

wherein the slip-controlling is performed until a car speed becomes larger than a second car speed.

9 . A non-transitory computer-readable record medium storing a program that, when executed by a processor, causes the processor to perform the method for controlling a hybrid electric vehicle according to claim 1 .

10 . A hybrid electric vehicle comprising:

an engine;

a driving motor;

an engine clutch disposed between the engine and the driving motor;

a step-variable transmission having an input terminal connected to the driving motor; and

a controller unit configured to

prohibit shifting of the step-variable transmission based on determining that a preconfigured deceleration braking condition is satisfied, and

slip-control the engine clutch based on determining that an acceleration pedal is operated before a car stop holding time while the shifting is prohibited, in which the preconfigured deceleration braking condition is maintained, exceeds a preconfigured reference time,

wherein the controller unit is configured to determine that the preconfigured deceleration braking condition is satisfied based on determining that a brake pedal is operated, a car speed is lower than a first car speed, and a braking torque is larger than a first torque, and

wherein the car stop holding time includes a time during which the car speed is maintained lower than the first car speed and the braking torque is maintained higher than the first torque.

11 . The hybrid electric vehicle of claim 10 ,

wherein the controller unit is further configured to allow shifting to a first stage based on determining that the car stop holding time exceeds the preconfigured reference time without the acceleration pedal being operated.

12 . The hybrid electric vehicle of claim 10 ,

wherein the controller unit is further configured to control torque to be output from i) the engine, ii) a starter/generator motor, and iii) the driving motor while the slip-control is performed.

13 . The hybrid electric vehicle of claim 12 ,

wherein the engine and the starter/generator motor are directly connected to each other.

14 . The hybrid electric vehicle of claim 10 ,

wherein the controller unit is further configured to raise a creep torque of a current shifting stage, based on a wheel torque output by a creep torque set for a first stage of the step-variable transmission, before the car stop holding time exceeds the preconfigured reference time.

15 . The hybrid electric vehicle of claim 14 ,

wherein the controller unit is further configured to compare a braking torque with a preconfigured second torque based on determining that the acceleration pedal is not operated before the car stop holding time exceeds the preconfigured reference time.

16 . The hybrid electric vehicle of claim 15 ,

wherein the controller unit is further configured to restore the raised creep torque based on determining that the braking torque is equal to or larger than the preconfigured second torque as a result of the comparison.

17 . The hybrid electric vehicle of claim 10 ,

wherein the controller unit is configured to perform slip-control until a car speed becomes larger than a preconfigured second car speed.