Engine idle operation control method and system for heating of hybrid electric vehicle

Patent metadata

Field	Value
Publication number	US-10220828-B2
Application number	US-201514928390-A
Country	US
Kind code	B2
Filing date	Oct 30, 2015
Priority date	Dec 3, 2014
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

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.

First claim

What is claimed is:

1. An engine idle operation control method for heating of a hybrid electric vehicle, comprising:
receiving, by a controller, an engine-on request for heating of the vehicle equipped with an engine and a first motor for driving the vehicle and a second motor power-transmittably connected to the engine when the engine is in a stop state;
determining, by the controller, a road condition on which the vehicle is traveling;
determining, by the controller, a target charge power controlling a power generation of the second motor and set as a value corresponding to the road condition and battery state information;
determining, by the controller, a basic idle revolutions per minute (RPM) set as a value corresponding to the road condition, the target charge power, and the outdoor temperature detected by an outdoor temperature sensor;
determining, by the controller, a compensation RPM based on a heating load of the vehicle;
determining, by the controller, a target idle RPM by compensating for the basic idle RPM by the compensation RPM; and
adjusting, by the controller, the engine idle driving into the determined target idle RPM during the heating of the vehicle,
wherein the road condition is determined as one selected from the group consisting of: a downtown road running condition, a national highway running condition, and an expressway running condition,
wherein the road condition is determined using the number of vehicle stops and the average speed of the vehicle for a previous set time,
wherein, under the downtown running condition, the engine idle operation region is determined as a region of high engine efficiency in the engine clutch lock-up impossible section by increasing the charge power by the second motor, and
wherein, under the national highway running condition or the expressway running condition, the battery charging is induced after the engine clutch lock-up by reducing the charge power by the second motor.

2. The engine idle operation control method of claim 1 , wherein when the vehicle is in a low speed running state where the average speed of the vehicle is equal to or less than a first reference speed and the number of vehicle stops is equal to or greater than a first reference number, a road on which the vehicle is traveling is determined as a downtown road having multiple congestion sections.

3. The engine idle operation control method of claim 2 , wherein when the vehicle is in a high speed running state where the average speed of the vehicle is equal to or greater than a second reference speed and the number of vehicle stops is equal to or less than a second reference number, a road on which the vehicle is traveling is determined as an expressway.

4. The engine idle operation control method of claim 2 , wherein when the average speed of the vehicle is less than the second reference speed while exceeding the first reference speed and the number of vehicle stops is less than the first reference number while exceeding the second reference number, a road on which the vehicle is traveling is determined as a national highway.

5. The engine idle operation control method of claim 1 , wherein the battery condition information includes a battery temperature and a battery State of Charge (SOC).

6. The engine idle operation control method of claim 5 , wherein the road condition is determined as one selected from the group consisting of: a downtown road running condition, a national highway running condition, and an expressway running condition, and a look-up table in which the target charge power is set as values based on the battery temperature and the battery SOC based on each road condition is used to determine the target charge power.

7. The engine idle operation control method of claim 1 , wherein the road condition is determined as one selected from the group consisting of: a downtown road running condition, a national highway running condition, and an expressway running condition, and a look-up table in which the basic idle RPM is set as values according to the target charge power and the outdoor temperature based on each road condition is used to determine the basic idle RPM.

8. The engine idle operation control method of claim 1 , wherein in the determination of the compensation RPM, the compensation RPM set as a value corresponding to the opening degree of a temperature door and the operation stage of an air conditioning blower as the heating load of the vehicle is determined.

9. The engine idle operation control method of claim 8 , wherein to determine the compensation RPM, a look-up table in which the compensation RPM is set as a value according to the opening degree of the temperature door and the operation stage of the air conditioning blower is used.

10. The engine idle operation control method of claim 1 , wherein in the determination of the target idle RPM, the target idle RPM is determined as a value obtained by adding the compensation RPM to the basic idle RPM.

11. An engine idle operation control system for heating of a hybrid electric vehicle, comprising:
a memory configured to store program instructions; and
a processor configured to execute the program instructions, the program instructions when executed configured to:
receive an engine-on request for heating of the vehicle equipped with an engine and a first motor for driving the vehicle and a second motor power-transmittably connected to the engine when the engine is in a stop state;
determine a road condition on which the vehicle is traveling;
determine a target charge power controlling a power generation of the second motor and set as a value corresponding to the road condition and battery state information;
determine a basic idle revolutions per minute (RPM) set as a value corresponding to the road condition, the target charge power, and the outdoor temperature detected by an outdoor temperature sensor;
determine a compensation RPM based on a heating load of the vehicle;
determine a target idle RPM by compensating for the basic idle RPM by the compensation RPM; and
adjust the engine idle driving into the determined target idle RPM during the heating of the vehicle,
wherein the road condition is determined as one selected from the group consisting of: a downtown road running condition, a national highway running condition, and an expressway running condition,
wherein the road condition is determined using the number of vehicle stops and the average speed of the vehicle for a previous set time,
wherein, under the downtown running condition, the engine idle operation region is determined as a region of high engine efficiency in the engine clutch lock-up impossible section by increasing the charge power by the second motor, and
wherein, under the national highway running condition or the expressway running condition, the battery charging is induced after the engine clutch lock-up by reducing the charge power by the second motor.

12. The system of claim 11 , wherein when the vehicle is in a low speed running state where the average speed of the vehicle is equal to or less than a first reference speed and the number of vehicle stops is equal to or greater than a first reference number, a road on which the vehicle is traveling is determined as a downtown road having multiple congestion sections.

13. The system of claim 12 , wherein when the vehicle is in a high speed running state where the average speed of the vehicle is equal to or greater than a second reference speed and the number of vehicle stops is equal to or less than a second reference number, a road on which the vehicle is traveling is determined as an expressway.

14.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Cho In Eok
• Han Hoon
• Choi Yong Kak
• Park Il Kwon

Classifications

• Y10S903/93

  Conjoint control of different elements · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60W20/15 Primary

  Control strategies specially adapted for achieving a particular effect · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W2710/0644

  Engine speed · CPC title