Method and control device for determining a desired intake manifold pressure of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-11208965-B2
Application number	US-201816218907-A
Country	US
Kind code	B2
Filing date	Dec 13, 2018
Priority date	Dec 13, 2017
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A method for determining a desired intake manifold pressure of an internal combustion engine by means of an iterative method, wherein a cylinder charge is determined for an intake manifold pressure iterated during the iterative method, and the desired intake manifold pressure is determined as a function of the cylinder air charge that has been determined. In addition, a control device for carrying out the method is provided.

First claim

What is claimed is:

1. A method for determining a desired intake manifold pressure of an internal combustion engine via an iterative method, the method comprising:
determining a cylinder charge for an intake manifold pressure iterated during the iterative method; and
determining the desired intake manifold pressure as a function of the cylinder charge that has been determined,
wherein the desired intake manifold pressure is an iterated value representing an improved initial value for a subsequent iteration.

2. A method for determining a desired intake manifold pressure of an internal combustion engine via an iterative method, the method comprising:
determining a cylinder charge for an intake manifold pressure iterated during the iterative method; and
determining the desired intake manifold pressure as a function of the cylinder charge that has been determined,
wherein the iterative method is a secant method.

3. The method according to claim 2 , wherein a cylinder charge is determined for a first initial intake manifold pressure, and a second initial intake manifold pressure is determined in that the cylinder charge for the first initial intake manifold pressure is compared with a desired cylinder charge of the internal combustion engine, and wherein the second initial intake manifold pressure is determined as a function of the result of the comparison between the cylinder charge for the first initial intake manifold pressure and the desired cylinder charge.

4. The method according to claim 3 , wherein the first initial intake manifold pressure is an actual intake manifold pressure.

5. The method according to claim 3 , wherein the iterated intake manifold pressure is determined based on the first initial intake manifold pressure and the second initial intake manifold pressure is determined via the secant method.

6. The method according to claim 5 , wherein the iterated intake manifold pressure is additionally determined as a function of the cylinder charge for the first initial intake manifold pressure and of the cylinder charge for the second initial intake manifold pressure.

7. A method for determining a desired intake manifold pressure of an internal combustion engine via an iterative method, the method comprising:
determining a cylinder charge for an intake manifold pressure iterated during the iterative method; and
determining the desired intake manifold pressure as a function of the cylinder charge that has been determined,
wherein the cylinder charge for the iterated intake manifold pressure is determined as a function of a desired exhaust gas back pressure, and wherein the desired exhaust gas back pressure is determined as a function of the iterated intake manifold pressure.

8. The method according to claim 7 , wherein the desired exhaust gas back pressure is determined from a quadratic approximation of the equation:

m
.

Abg

=

A
eff

⁢

p
3

⁢

2

R
s

⁢

T
3

⁢

ψ
⁡

(

c
d

;

p
4

p
3

)

,

wherein {dot over (m)} Abg is a desired exhaust gas mass flow, A eff is an effective opening area of a throttle, p 3 is a desired exhaust gas back pressure, p 4 is a desired pressure after a turbine, R s is the specific gas constant of the exhaust gas, T 3 is an exhaust gas temperature before the turbine, c d is a turbine flow factor and ψ(·) is a flow function.

9. The method according to claim 7 , wherein the desired exhaust gas back pressure is determined by an iterative method.

10. The method according to claim 9 , wherein an initial exhaust gas back pressure is the iterated intake manifold pressure.

11. The method according to claim 10 , wherein a reduced exhaust gas mass flow and a VTG drive duty cycle are determined as a function of the initial exhaust gas back pressure, and the iterated exhaust gas back pressure is determined as a function thereof.

12. The method according to claim 7 , wherein the desired intake manifold pressure is determined from a desired pressure after a turbine and from a power balance of the turbine and of a compressor.

13. A method comprising:
determining a desired exhaust gas back pressure of an internal combustion engine via a fixed-point method; and
determining an iterated exhaust gas back pressure from a quadratic approximation of the equation:

m
.

Abg

=

A
eff

⁢

p
3

⁢

2

R
s

⁢

T
3

⁢

ψ
⁡

(

c
d

;

p
4

p
3

)

,

wherein {dot over (m)} Abg is a desired exhaust gas mass flow, A eff is an effective opening area of a throttle, p 3 is the desired exhaust gas back pressure, p 4 is a desired pressure after a

Assignees

• Volkswagen Ag

Inventors

• Heinken Sebastian
• Bunjes Marco
• Thaler Tim
• Frank Benjamin
• Beese Daniel

Classifications

• F02D2200/0411

  Volumetric efficiency · CPC title

• F02D41/145

  with determination means using an estimation · CPC title

• F02D41/1406 Primary

  with use of a optimisation method, e.g. iteration · CPC title

• F02D41/0007

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D2250/34

  Control of exhaust back pressure, e.g. for turbocharged engines · CPC title