Abstract: An air conditioning system of a vehicle and a control method thereof, includes a distance sensor that is configured to detect a distance from the vehicle to another vehicle in front of the vehicle; a humidity sensor that is configured to detect an inside humidity of the vehicle; an inside temperature sensor that is configured to detect an inside temperature of the vehicle; an outside temperature sensor that is configured to detect an outside temperature of the vehicle; and a controller electrically connected to the distance sensor, the humidity sensor, the inside temperature sensor, and the outside temperature sensor and configured for determining an air conditioning mode of the vehicle based on the distance to another vehicle in front detected by the distance sensor, the inside humidity of the vehicle detected by the humidity sensor, the inside temperature of the vehicle detected by the inside temperature sensor, and the outside temperature of the vehicle detected by the outside temperature sensor.

Abstract: A state of charge (SOC) control method for improving fuel efficiency of a hybrid vehicle may include monitoring an SOC of a battery of the vehicle, determining, by a controller, a change rate in SOC reduction based on the monitored SOC, and performing, by the controller, SOC anti-reduction control based on the determined change rate in the SOC reduction.

Abstract: An apparatus for controlling an engine of a vehicle includes an engine managing part to control warming up the engine at an initial start stage, and an air conditioning controlling part to request the engine managing part to perform an engine start, depending on whether the engine is warming up when control of air conditioning is necessary. The air conditioning controlling part continuously requests the engine managing part to perform the engine start to control the air conditioning until a warming up duration of the engine is terminated during the warning up of the engine.

Abstract: A method of controlling a hybrid electric vehicle is provided. The method includes determining whether a condition for turning off an engine is satisfied and determining engine clutch disengaging time and residual purge gas consuming time from engine driving status information when the condition is satisfied. Engine clutch-engaged charging control time is determined from the engine clutch disengaging time and the residual purge gas consuming time. The method includes closing a purge control solenoid valve and starting to perform engine clutch-engaged charging control. The engine clutch-engaged charging control is maintained for the determined engine clutch-engaged charging control time and then engine clutch disengaging control is performed for the determined engine clutch disengaging time. The engine is stopped after the engine clutch disengaging control is performed.

Abstract: An engine control method for heating of a hybrid electric vehicle, includes collecting information for air conditioning control by a sensor during an operation of a heating, ventilation, and air conditioning (HVAC) device in the hybrid electric vehicle in which forced engine driving for heating is performed, determining whether a condition that requires pre-engine driving as driving in a separate mode from forced engine driving is satisfied based on the collected information, upon determining that the condition that requires the pre-engine driving is required is satisfied, determining whether a condition for allowing the pre-engine driving is satisfied based on engine efficiency and hybrid system efficiency information, and upon determining that the condition for allowing the pre-engine driving is satisfied, performing the pre-engine driving for driving an engine to manage engine coolant temperature.

Abstract: A method for controlling a hybrid vehicle having a motor and an engine includes: calculating a first startup reference value of the engine on the basis of requested power of the hybrid vehicle; measuring a current speed of the hybrid vehicle, and predicting a future speed of the hybrid vehicle; generating a compensation value needed to compensate for the first startup reference value of the engine on the basis of a difference between the current speed and the future speed of the hybrid vehicle; acquiring a second startup reference value of the engine by compensating for the first startup reference value on the basis of the compensation value; and controlling a startup operation of the engine according to the second startup reference value acquired through compensation.

Abstract: A method of controlling a hybrid electric vehicle is provided. The method includes determining whether a condition for turning off an engine is satisfied and determining engine clutch disengaging time and residual purge gas consuming time from engine driving status information when the condition is satisfied. Engine clutch-engaged charging control time is determined from the engine clutch disengaging time and the residual purge gas consuming time. The method includes closing a purge control solenoid valve and starting to perform engine clutch-engaged charging control. The engine clutch-engaged charging control is maintained for the determined engine clutch-engaged charging control time and then engine clutch disengaging control is performed for the determined engine clutch disengaging time. The engine is stopped after the engine clutch disengaging control is performed.

Abstract: An engine control method for heating of a hybrid electric vehicle, includes collecting information for air conditioning control by a sensor during an operation of a heating, ventilation, and air conditioning (HVAC) device in the hybrid electric vehicle in which forced engine driving for heating is performed, determining whether a condition that requires pre-engine driving as driving in a separate mode from forced engine driving is satisfied based on the collected information, upon determining that the condition that requires the pre-engine driving is required is satisfied, determining whether a condition for allowing the pre-engine driving is satisfied based on engine efficiency and hybrid system efficiency information, and upon determining that the condition for allowing the pre-engine driving is satisfied, performing the pre-engine driving for driving an engine to manage engine coolant temperature.

Abstract: An engine idle operation control method and system are provided to improve the fuel efficiency of a vehicle through maintenance of efficient battery SOC and charge control during the engine-on for heating of a vehicle. The method includes receiving an engine-on request for heating of the vehicle and determining a road condition. A target charge power is determined and set as a value corresponding to the road condition and battery state information. A basic idle RPM set as a value corresponding to the road condition, the target charge power, and the outdoor temperature is determined. A compensation RPM and a target idle RPM are determined by compensating for the basic idle RPM by the compensation RPM to adjust the engine idle driving into the determined target idle RPM during the heating of the vehicle.

Abstract: A heating control method of a hybrid vehicle controls engine driving for heating or revolutions per minute (RPM) of an engine according to whether the engine is started in a state in which navigation information is received to actively control a heating value of the engine and to improve fuel efficiency on an actual road in cold weather conditions, and for controlling the RPM of the engine to an appropriate RPM to smoothly recharge a battery with a high voltage through a hybrid starter generator (HSG).

Abstract: A method for controlling a hybrid vehicle having a motor and an engine includes: calculating a first startup reference value of the engine on the basis of requested power of the hybrid vehicle; measuring a current speed of the hybrid vehicle, and predicting a future speed of the hybrid vehicle; generating a compensation value needed to compensate for the first startup reference value of the engine on the basis of a difference between the current speed and the future speed of the hybrid vehicle; acquiring a second startup reference value of the engine by compensating for the first startup reference value on the basis of the compensation value; and controlling a startup operation of the engine according to the second startup reference value acquired through compensation.

Abstract: A method and an apparatus for controlling engine start for a hybrid electric vehicle are provided. The apparatus includes a data detector that is configured to detect data for controlling start of an engine. Additionally, a controller is configured to calculate a demand power of a driver based on the data and start the engine when the demand power of the driver is greater than an engine-on power line which is a reference for starting the engine.

Abstract: An engine control method of a hybrid vehicle for controlling the engine depending on an engine load of the hybrid vehicle includes: learning a change amount of an engine load; determining at least one engine torque depending on a magnitude of the engine load; calculating an optimum torque value by using the learned change amount of the engine load and at least one determined engine torque; and controlling the engine by using the calculated optimum torque value.

Abstract: An apparatus and a method are provided for controlling a mode change of a hybrid electric vehicle that change a mode of the hybrid electric vehicle at an optimal reference point of mode change when a demand power of a driver is stably maintained to be greater than a predetermined level. The method includes calculating a demand power or a demand torque of a driver and determining whether the demand power or the demand torque is maintained to be equal to or greater than a first predetermined value for a first predetermined time. A mode change hysteresis line is raised when the demand power or the demand torque is maintained to be equal to or greater than the first predetermined value for the first predetermined time and then a mode change is executed based on the raised mode change hysteresis line.

Abstract: An engine control method of a hybrid vehicle for controlling the engine depending on an engine load of the hybrid vehicle includes: learning a change amount of an engine load; determining at least one engine torque depending on a magnitude of the engine load; calculating an optimum torque value by using the learned change amount of the engine load and at least one determined engine torque; and controlling the engine by using the calculated optimum torque value.

Abstract: A method and an apparatus for controlling engine start for a hybrid electric vehicle are provided. The apparatus includes a data detector that is configured to detect data for controlling start of an engine. Additionally, a controller is configured to calculate a demand power of a driver based on the data and start the engine when the demand power of the driver is greater than an engine-on power line which is a reference for starting the engine.

Abstract: An apparatus and a method are provided for controlling a mode change of a hybrid electric vehicle that change a mode of the hybrid electric vehicle at an optimal reference point of mode change when a demand power of a driver is stably maintained to be greater than a predetermined level. The method includes calculating a demand power or a demand torque of a driver and determining whether the demand power or the demand torque is maintained to be equal to or greater than a first predetermined value for a first predetermined time. A mode change hysteresis line is raised when the demand power or the demand torque is maintained to be equal to or greater than the first predetermined value for the first predetermined time and then a mode change is executed based on the raised mode change hysteresis line.

Abstract: An engine idle operation control method and system are provided to improve the fuel efficiency of a vehicle through maintenance of efficient battery SOC and charge control during the engine-on for heating of a vehicle. The method includes receiving an engine-on request for heating of the vehicle and determining a road condition. A target charge power is determined and set as a value corresponding to the road condition and battery state information. A basic idle RPM set as a value corresponding to the road condition, the target charge power, and the outdoor temperature is determined. A compensation RPM and a target idle RPM are determined by compensating for the basic idle RPM by the compensation RPM to adjust the engine idle driving into the determined target idle RPM during the heating of the vehicle.

Abstract: Disclosed are apparatuses and methods for controlling driving of a hybrid vehicle. A method may include calculating a rate-of-change of a motor rpm, calculating a second reference rpm depending on the calculated rate-of-change of the motor rpm by varying a first reference rpm that has been set to engage an engine clutch, where the second reference rpm is newly set to engage the engine clutch, and controlling a vehicle drive mode by determining whether to start an engine and engage the engine clutch according to whether the motor rpm reaches the second reference rpm.