Method for controlling exhaust gas recirculation system for engine

Patent metadata

Field	Value
Publication number	US-9890749-B2
Application number	US-201514878790-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Dec 2, 2014
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A method for controlling an exhaust gas recirculation (EGR) system which is provided with an intake throttle valve and an EGR valve driven by a motor may include detecting an engine speed and an amount of intake air for each cylinder of an engine while the engine is operating, determining an amount of air flow supplied to the engine based on the engine speed and the amount of intake air for each cylinder, determining an equivalent cross-section of the EGR valve based on the amount of air flow, determining an opening angle of the EGR valve based on the engine speed, the amount of intake air for each cylinder, the amount of air flow, and the equivalent cross-section of the EGR valve, and controlling the EGR valve according to the opening angle of the EGR valve.

First claim

What is claimed is:

1. A method for controlling an exhaust gas recirculation (EGR) system which is provided with an intake throttle valve and an EGR valve driven by a motor, the method comprising:
detecting, by an engine controller, an engine speed and an amount of intake air for each cylinder of an engine while the engine is operating;
determining, by the engine controller, an amount of air flow supplied to the engine based on the engine speed and the amount of intake air for each cylinder;
determining, by the engine controller, an equivalent cross-section of the EGR valve based on an amount of an EGR gas passed through the EGR valve;
determining, by the engine controller, an opening angle of the EGR valve based on the engine speed, the amount of intake air for each cylinder, the amount of air flow, and the equivalent cross-section of the EGR valve; and
controlling, by the engine controller, the EGR valve according to the opening angle of the EGR valve,
wherein the opening angle of the EGR valve is calculated through the following equation: θ=f 2 (A RED ,M AIR ,N), wherein A RED is an axis of the equivalent cross-section of the EGR valve, N is the engine speed, and M AIR is the amount of intake air for each cylinder,
wherein the opening angle of the EGR valve is formed as a 3-dimensional map with respect to the equation for calculating the opening angle of the EGR valve, and
wherein the 3-dimensional map includes an axis of the engine speed, an axis of the amount of intake air for each cylinder of the engine, and the axis of the equivalent cross-section of the EGR valve.

2. The method of claim 1 , wherein the amount of air flow is determined through the following equation:

m
.

AIR

=

n
2

⁢

2
⁢

⁢
π
⁢

⁢
N

60

⁢

M
AIR

,

wherein {dot over (m)} AIR is the amount of air flow, n is a number of cylinders of the engine, N is the engine speed, and M AIR is the amount of intake air for each cylinder.

3. The method of claim 1 , wherein the equivalent cross-section of the EGR valve is determined through the following equation:

A
RED

=

m
.

EGR

2
⁢
γ

(

γ
-
1

)

⁢

RT
EGRV

⁢

P
EGRV

⁢

Ψ
EGR

,

and wherein:
A RED is the equivalent cross-section of the EGR valve,

Ψ
EGR

=

{

(

P
COMP

P
EGRV

)

2
γ

-

(

P
COMP

P
EGRV

)

γ
+
1

γ

⁢

,

P
COMP

P
EGRV

>
0.52

0.2588
,

P
COMP

P
EGR

Assignees

• Hyundai Motor Co Ltd

Inventors

• Han Dong Hee
• Kim Yoon Joo
• Choi Kwanhee
• Lim Hyun Jun
• Lee Joowon
• Joo Nahm Roh
• Park Jong Il

Classifications

• F02M26/52 Primary

  Systems for actuating EGR valves · CPC title

• F02D41/0065

  Specific aspects of external EGR control (constructional details of EGR system F02M26/00) · CPC title

• F02D41/18

  by measuring intake air flow · CPC title

• Y02T10/47

  Cross-Sectional Technologies · mapped topic

• F02M26/51

  EGR valves combined with other devices, e.g. with intake valves or compressors (combined with intake air throttles F02M26/64) · CPC title