Apparatus and method for displaying distance to empty of vehicle

1. An apparatus for displaying a distance to empty of a vehicle, comprising a controller configured to:

estimate a state of a mass of the vehicle, which increases or decreases while the vehicle is running;

calculate a driving energy consumption using a past-learned energy consumption based on a mass level corresponding to the increased or decreased mass of the vehicle while the vehicle is running, and a current energy consumption of the vehicle;

calculate the distance to empty of the vehicle based on the driving energy consumption;

determine whether to update the distance to empty displayed on a display based on the mass level;

update display information on the display based on the distance to empty;

extract the past-learned energy consumption corresponding to the mass level of the vehicle among past-learned energy consumptions for previously-learned respective mass levels;

calculate the driving energy consumption of the vehicle by applying the extracted past-learned energy consumption and the current energy consumption of the vehicle at a predetermined rate;

determine an application rate of the current energy consumption in the driving energy consumption to about 100% when a remaining SOC is smaller than a first reference value;

determine the application rate of the current energy consumption in the driving energy consumption to about 0% when the remaining SOC is equal to or greater than a second reference value; and

adjust the application rate of the current energy consumption in the driving energy consumption to be inversely proportional to the remaining SOC when the remaining SOC is equal to or greater than the first reference value and smaller than the second reference value.

2. The apparatus of claim 1 , wherein the controller is configured to update the distance to empty displayed on the display when the mass level is different from an initial mass level of the vehicle.

3. The apparatus of claim 1 , wherein the controller is configured to estimate the state of the mass of the vehicle based on at least one of a reducer efficiency, a motor torque, a running load, a vehicle speed, or a road gradient of the running vehicle.

4. The apparatus of claim 1 , wherein the controller is further configured to calculate an additional-use energy consumption based on a travel distance of the vehicle and an air conditioner-use power of the vehicle when an air conditioning system in the vehicle operates in an ON state.

5. The apparatus of claim 4 , wherein the controller is configured to:

calculate a charge/discharge energy consumption gain depending on a gradient of a road ahead; and

add the charge/discharge energy consumption gain to the additional-use energy consumption.

6. The apparatus of claim 4 , wherein the controller is configured to calculate the distance to empty of the vehicle based on the driving energy consumption and the additional-use energy consumption of the vehicle.

7. The apparatus of claim 1 , wherein the controller is further configured to inform a state of change in the distance to empty due to the increased or decreased mass on the display during a predetermined time before updating the display information on the display when the distance to empty displayed on the display is determined to be updated.

8. A method for displaying a distance to empty of a vehicle, comprising steps of:

estimating a state of a mass of the vehicle, which increases or decreases while the vehicle is running;

determining whether to update the distance to empty displayed on a display based on a mass level corresponding to the increased or decreased mass of the vehicle while the vehicle is running;

calculating a driving energy consumption using a past-learned energy consumption based on the mass level while the vehicle is running, and a current energy consumption of the vehicle;

calculating the distance to empty of the vehicle based on the driving energy consumption;

updating display information on the display based on the distance to empty;

extracting the past-learned energy consumption corresponding to the mass level of the vehicle among past-learned energy consumptions for previously-learned respective mass levels;

calculating the driving energy consumption of the vehicle by applying the extracted past-learned energy consumption and the current energy consumption of the vehicle at a predetermined rate;

determining an application rate of the current energy consumption in the driving energy consumption to about 100% when a remaining SOC is smaller than a first reference value;

determining the application rate of the current energy consumption in the driving energy consumption to about 0% when the remaining SOC is equal to or greater than a second reference value; and

adjusting the application rate of the current energy consumption in the driving energy consumption to be inversely proportional to the remaining SOC when the remaining SOC is equal to or greater than the first reference value and smaller than the second reference value.

9. The method of claim 8 , wherein the step of determining whether to update the distance to empty comprises updating the distance to empty displayed on the display when the mass level is different from an initial mass level of the vehicle.

10. The method of claim 8 , wherein the step of estimating a state of a mass of the vehicle comprises estimating the state of the mass of the vehicle based on at least one of a reducer efficiency, a motor torque, a running load, a vehicle speed, or a road gradient of the vehicle running.

11. The method of claim 8 , further comprising a step of calculating an additional-use energy consumption based on a travel distance of the vehicle and an air conditioner-use power of the vehicle when an air conditioning system in the vehicle operates in an ON state.

12. The method of claim 11 , wherein the step of calculating an additional-use energy consumption comprises:

calculating a charge/discharge energy consumption gain depending on a gradient of a road ahead; and

adding the charge/discharge energy consumption gain to the additional-use energy consumption.

13. The method of claim 11 , wherein the step of calculating the distance to empty of the vehicle comprises calculating the distance to empty of the vehicle based on the driving energy consumption and the additional-use energy consumption of the vehicle.

14. The method of claim 8 , further comprising a step of informing a state of change in the distance to empty due to the increase or decrease of the mass on the display during a predetermined time before the display information on the display is updated when the distance to empty displayed on the display is determined to be updated.