Engine operation control system and method of eco-friendly vehicle

Patent metadata

Field	Value
Publication number	US-9744965-B2
Application number	US-201514958023-A
Country	US
Kind code	B2
Filing date	Dec 3, 2015
Priority date	Sep 2, 2015
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

An engine operation control system and method of an eco-friendly vehicle are provided to achieve optimal engine operating efficiency by changing a region for using an engine operating point based on a battery state of charge (SOC) region and a driver requirement torque. The system and method satisfy a driver requirement torque and achieve defense of battery state of charge (SOC) and optimal engine operating efficiency by changing an engine operating point based on a battery state of charge (SOC) and a driver requirement torque to an engine operating point where a battery discharge amount is minimized and a battery charging amount is maximized.

First claim

What is claimed is:

1. An engine operation control system of an eco-friendly vehicle, comprising:
a controller comprising a battery state of charge (SOC) determination unit connected to a battery and configured to:
determine a battery SOC state; and
change and adjust an engine operating point based on the determined battery SOC state and a driver requirement torque,
wherein when the battery SOC state is in a normal state that is greater than a normal SOC threshold, the controller is configured to drive the vehicle with an engine operating point in an optimal operating line (OOL) of an engine, and when the battery SOC state is equal to or less than the normal SOC threshold, the controller is configured to change and adjust the engine operating point based on a comparison result between the driver requirement torque and an engine torque in an OOL of the engine, and
wherein the controller is configured to drive the vehicle with an engine operating point in an exhaust gas recirculation (EGR) max line when the battery SOC state is in a low state that is less than the normal SOC threshold and the driver requirement torque is greater than the engine torque in the OOL.

2. The engine operation control system of claim 1 , wherein the controller is configured to add a motor operating torque to an engine torque in an OOL when the battery SOC state is in the normal state that is greater than the normal SOC threshold and a torque greater than the engine torque in the OOL is required as the driver requirement torque.

3. The engine operation control system of claim 1 , wherein the controller is configured to maintain an engine operating point as an OOL and simultaneously drive a motor to generate electricity for battery charging when the battery SOC state is in the normal state that is greater than the normal SOC threshold and a torque less than the engine torque in the OOL is required as the driver requirement torque.

4. The engine operation control system of claim 1 , wherein the controller is configured to add a motor operating torque to the engine torque in the EGR max line when the battery SOC state is in the low state that is greater than a low SOC threshold and a torque greater than the engine torque in the EGR max line is required as the driver requirement torque.

5. The engine operation control system of claim 1 , wherein the controller is configured to maintain an engine operating point as an OOL and simultaneously drive a motor to generate electricity for battery charging when the battery SOC state is in the low state that is greater than a low SOC threshold and a torque less than the engine torque in the OOL is required as the driver requirement torque.

6. The engine operation control system of claim 1 , wherein the controller is configured to drive the vehicle with an engine operating point in a part-load max line when the battery SOC state is in a very low state, that is less than the normal SOC threshold, that is greater than a very low SOC threshold and the driver requirement torque is greater than the engine torque in the OOL.

7. The engine operation control system of claim 6 , wherein the controller is configured to add a motor operating torque to an engine torque in a part-load max line when the battery SOC state is in the very low state that is greater than the very low SOC threshold and a torque greater than the engine torque in the part-load max line is required as the driver requirement torque.

8. The engine operation control system of claim 6 , wherein the controller is configured to maintain an engine operating point as an OOL and simultaneously drive a motor to generate electricity for battery charging when the battery SOC state is in the very low state that is greater than the very low SOC threshold and a torque less than the engine torque in the OOL is required as the driver requirement torque.

9. The engine operation control system of claim 1 , wherein the controller is configured to drive the vehicle with an engine operating point in a full-load max line satisfying a maximum driver requirement torque when the battery SOC state is in a battery SOC state that reaches a critically low level that is less than the normal SOC threshold and the driver requirement torque is higher than the engine torque in the OOL.

10. The engine operation control system of claim 9 , wherein the controller is configured to drive a motor to generate electricity for battery charging irrespective of a driver requirement torque when the battery SOC state is in a battery SOC state that reaches the critically low level and the vehicle is driven with an engine operating point in a full-load max line.

11. The engine operation control system of claim 9 , wherein the controller is configured to maintain an engine operating point as an OOL and simultaneously drive the motor to generate electricity for battery charging when the battery SOC state is in a battery SOC state that reaches the critically low level and a torque less than the engine torque in the OOL is required as the driver requirement torque.

12. An engine operation control method of an eco-friendly vehicle, comprising:
determining, by a controller, a battery state of charge (SOC) state;
determining, by the controller, a driver requirement torque; and
changing and adjusting, by the controller, an engine operating point based on the determined battery SOC state and driver requirement torque,
wherein, when the battery SOC state is in a normal state that is greater than a normal SOC threshold, the vehicle is driven with an engine operating point in an optimal operating line (OOL) of an engine, and when the battery SOC state is in equal to or less than the normal SOC threshold, the engine operating point is changed and adjusted based a comparison result between the driver requirement torque and an engine torque in an OOL of the engine, and
wherein the changing and adjusting includes driving, by the controller, the vehicle with an engine operating point in an exhaust gas recirculation (EGR) max line when the battery SOC state is in a low state that is less than the normal SOC threshold and the driver requirement torque is greater than the engine torque in the OOL.

13. The method according to claim 12 , wherein the changing and adjusting includes adding, by the controller, a motor operating torque to an engine torque in an OOL when the battery SOC state is in the normal state that is greater than the normal SOC threshold and a torque greater than the engine torque in the OOL is required as the driver requirement torque.

14. The method according to claim 12 , wherein the changing and adjusting includes maintaining, by the controller, an engine operating point as an OOL and simultaneously driving a motor to generate electricity for battery charging when the battery SOC state is in the normal state that is greater than the normal SOC threshold and a torque less than the engine torque in the OOL is required as the driver requirement torque.

15. The method according to claim 12 , wherein the changing and adjusting includes adding, by the controller, a motor operating torque to the engine torque in the EGR max line when the battery SOC state is in the low state that is greater than a low SOC threshold and a torque greater than the engine torque in the EGR max line is required as the driver requirement torque.

16. The method according to claim 12 , wherein the changing and adjusting includes maintaining, by the controller, an engine operating point as an OOL and simultaneously driving a motor to generate electricity for battery charging when the battery SOC state is in the low s

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Choi Yong Kak
• Lee Chun Hyuk
• Park Tae Wook

Classifications

• B60W10/08

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

• B60W20/16

  for reducing engine exhaust emissions · CPC title

• Y10S903/93

  Conjoint control of different elements · CPC title

• B60W30/1882

  characterised by the working point of the engine, e.g. by using engine output chart · CPC title

• B60W2540/10

  Accelerator pedal position · CPC title