Method and control system for operating a turbocharged internal combustion engine of a motor vehicle

Patent metadata

Field	Value
Publication number	US-10508605-B2
Application number	US-201615544953-A
Country	US
Kind code	B2
Filing date	Nov 5, 2016
Priority date	Jan 23, 2015
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

A method for operating an internal combustion engine having a turbocharger, wherein a fuel quantity is supplied to the combustion chamber of the engine in a stationary state, which fuel quantity is determined according to a first predetermined relationship between a load requirement to the engine and a rating determining a fuel quantity to be supplied to the combustion chamber, wherein a second predetermined relationship between the rating and the load requirement is used, wherein according to the second relationship, a given load requirement is assigned a larger quantity of fuel than according to the first relationship. In a transient state of the engine, the fuel quantity supplied to the combustion chamber is determined based on an interpolated value of the rating, which is determined for the rating by an interpolation between a value resulting from the first relationship and a value resulting from the second relationship.

First claim

The invention claimed is:

1. A method for operating an internal combustion engine having at least one turbocharger, comprising:
via a central engine control unit,
presetting a first predetermined relationship between an engine load requirement and a rated engine operating variable;
presetting a second predetermined relationship between a given engine load requirement and a given rated engine operating variable;
wherein the quantity of fuel according to the second relationship of the given load requirement is greater than the quantity of fuel according to the first predetermined relationship;

in a steady state of the internal combustion engine, injecting a quantity of fuel to a combustion chamber of the internal combustion engine based on the first predetermined relationship; and
in a transient state of the internal combustion engine, injecting the quantity of fuel fed to the combustion chamber based on an interpolated value of the rated variable obtained by interpolation between a value for the rated engine operating variable, resulting from the first predetermined relationship, and a value for the rated variable, resulting from the second predetermined relationship; and
further including:
carrying out the interpolation, via the central engine control unit, as a function of a differential rotational speed;
wherein the differential rotational speed is calculated as a difference between a setpoint rotational speed and an instantaneous actual rotational speed.

2. The method according to claim 1 , further including:
via the central engine control unit,
optimizing the first predetermined relationship with respect to reduced emissions of the internal combustion engine.

3. The method according to claim 1 , including using a characteristic diagram, in which values for the rated engine operating variable of the first predetermined relationship and the second predetermined relationship are stored as a function of a rotational speed and a torque of the internal combustion engine.

4. The method according to claim 1 , including using a lambda setpoint value as the rated engine operating variable for the internal combustion engine.

5. The method according to claim 1 , further including:
via the central engine control unit,
retarding ignition time, in a transient state of the internal combustion engine based on an interpolation between a first predetermined ignition time relationship, given between a load requirement of the internal combustion engine and the ignition time, and a second predetermined ignition time relationship, given between the load requirement and the ignition time;
wherein an additional rated engine operating variable is combined with the interpolated value of the rated engine operating variable;
wherein the additional rated engine operating variable is calculated based on scaling of a rated engine operating variable differential value;
wherein the rated engine operating variable differential value is calculated as a difference between a value of the rated engine operating variable, which results from a third predetermined relationship being given between the rated engine operating variable and the load requirement, and the value of the rated engine operating variable of the second predetermined relationship; and
 wherein the third relationship represents a knocking limit of the internal combustion engine at the ignition time being/having been retarded.

6. The method according to claim 1 , wherein the second relationship represents a knocking limit of the internal combustion engine.

7. An internal combustion engine having at least one turbocharger, comprising:
an engine block having a combustion chamber;
a fuel injection device; and
a control device having computer executable instructions stored on an electronic medium for:
presetting a first predetermined relationship between an engine load requirement and a rated engine operating variable;
presetting a second predetermined relationship between a given engine load requirement and a given rated engine operating variable;
wherein the quantity of fuel according to the second relationship of the given load requirement is greater than the quantity of fuel according to the first predetermined relationship;

in a steady state of the internal combustion engine, injecting a quantity of fuel to a combustion chamber of the internal combustion engine based on the first predetermined relationship; and
in a transient state of the internal combustion engine, injecting the quantity of fuel fed to the combustion chamber based on an interpolated value of the rated variable obtained by interpolation between a value for the rated engine operating variable, resulting from the first predetermined relationship, and a value for the rated variable, resulting from the second predetermined relationship; and
wherein the control device carries out the interpolation as a function of a differential rotational speed;
wherein the differential rotational speed is calculated as a difference between a setpoint rotational speed and an instantaneous actual rotational speed.

8. The internal combustion engine according to claim 7 , wherein the internal combustion engine is a gas engine.

9. The internal combustion engine according to claim 8 , wherein the internal combustion engine is a lean gas engine.

10. A motor vehicle, comprising:
an internal combustion engine having at least one turbocharger and including:
an engine block with a combustion chamber;
a fuel injection device; and
a control device having computer executable instructions stored on an electronic medium for:
preset/presetting a first predetermined relationship between an engine load requirement and a rated engine operating variable;
preset/presetting a second predetermined relationship between a given engine load requirement and a given rated engine operating variable;
wherein the quantity of fuel according to the second relationship of the given load requirement is greater than the quantity of fuel according to the first predetermined relationship;

in a steady state of the internal combustion engine, injecting a quantity of fuel to a combustion chamber of the internal combustion engine based on the first predetermined relationship; and

in a transient state of the internal combustion engine, injecting the quantity of fuel fed to the combustion chamber based on an interpolated value of the rated variable obtained by interpolation between a value for the rated engine operating variable, resulting from the first predetermined relationship, and a value for the rated variable, resulting from the second predetermined relationship; and
wherein the control device carries out the interpolation as a function of a differential rotational speed;
wherein the differential rotational speed is calculated as a difference between a setpoint rotational speed and an instantaneous actual rotational speed.

Assignees

• Mtu Friedrichshafen Gmbh

Inventors

• Bernhard Alexander
• Fimml Wolfgang

Classifications

• F02D41/2416

  Interpolation techniques · CPC title

• F02D41/0007 Primary

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

• F02D41/2422

  Selective use of one or more tables · CPC title

• F02D41/10

  for acceleration · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title