PROCEDURE FOR DETERMINING A FUEL COMPOSITION OR A FUEL QUALITY

• US 20090223485A1
• Filed: 12/04/2008
• Published: 09/10/2009
• Est. Priority Date: 12/14/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: HAMEDOVIC, Haris, Fischer, Wolfgang, Karrelmeyer, Roland, Loeffler, Axel, Graf, Gerald
• Granted Patent: US 8,068,971 B2
• Time in Patent Office: Days
• US Class Current: 123/435
• CPC Class Codes: F02D 19/061 by controlling fuel injectors
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 19/088 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

The invention concerns a procedure for determining the composition of a fuel mixture from a first fuel and a second fuel or for determining the quality of a fuel for operating a combustion engine with at least one cylinder pressure sensor in at least one cylinder of the combustion engine for determining the pressure history during a combustion process and a cylinder pressure based motor regulation for regulating the load and the combustion situation of the combustion engine. It is thereby provided that the determination of the composition of the fuel mixture or the quality of the fuel takes place with the aid of regulator information of the cylinder-pressure-based motor regulation. The procedure enables the continuing determination of the composition of the fuel mixture and the quality of the fuel at cylinder-pressure-based motor regulations without additional components as for example an ethanol sensor.

Claims

1. A method of determining the composition of a fuel mixture from a first fuel and a second fuel and the quality of a fuel for operating a combustion engine, wherein at least one cylinder pressure sensor in at least one cylinder of the combustion engine is provided for determining a pressure history during a combustion process, and wherein a cylinder pressure based motor regulation is provided for regulating a load and a combustion situation of the combustion engine, the method comprising:

determining the composition of the fuel mixture and the quality of the fuel with the aid of a plurality of regulator information of the cylinder-pressure-based motor regulation.

2. A method according to claim 1, further comprising determining the composition of the fuel mixture and the quality of the fuel by at least one of:

a plurality of control variable corrections; and

a plurality of control deviations.

3. The method according to claim 2, further comprising determining the composition of the fuel mixture and the quality of the fuel by at least one of:

a control variable correction of an injection quantity;

a control variable correction of an injection point of time;

a control variable correction of an ignition timing;

a control deviation of an average induced pressure during a combustion cycle;

a control deviation of an average combustion situation;

a control variable correction; and

a control deviation of a parameter deduced from at least one of the pre-mentioned factors.

4. A method according to claim 3, further comprising sending the control variable correction of the injection quantity;

the control variable correction of the injection point of time;

the control variable correction of the ignition timing;

the control deviation of the average induced pressure during a combustion cycle; and

the control deviation of the average combustion situation to a classifier, wherein the composition of the fuel mixture and the quality of the fuel are determined by the classifier as one or more output variables, and wherein the one or more output variables are sent to an engine control.

5. The method according to claim 4, further comprising determining the composition of the fuel mixture and the quality of the fuel at the classifier from one of:

an engine map; and

a data-based calculation model.

6. The method according to claim 5, further comprising supplying the classifier with one or more cylinder-pressure-based parameters chosen from a list including:

a maximum pressure gradient;

a status of the maximum pressure gradient;

a combustion duration;

a maximum pressure;

a released total energy;

a maximum released differential energy amount;

a status of the maximum released differential energy amount; and

a measure for the combustion stability.

7. The method according to claim 6, further comprising supplying the classifier with one or more parameters for an atmosphere pressure and an outside temperature.

8. The method according to claim 7, further comprising activating the classifier at one of:

a stationary operating condition of the combustion engine;

an idle mode of the combustion engine;

above a default operating temperature of the combustion engine;

in the presence of a predetermined atmosphere pressure; and

in the presence of a predetermined outside temperature range.

9. The method according to claim 8, further comprising making a rough determination of the composition of the fuel mixture and the quality of the fuel during a starting phase and/or a warm up phase of the combustion engine, wherein at at least one following operating phase of the combustion engine a precise determination of the composition of the fuel mixture and the quality of the fuel occurs.

10. The method according to claim 1, further comprising implementing a plurality of functions of the cylinder-pressure-based motor regulation and a classifier as a program code stored in one of:

a superior engine control; and

a separate hardware component.

11. The method according to claim 1, further comprising determining at least one of:

a composition of a gasoline/alcohol fuel mixture;

a composition of a diesel/biodiesel fuel composition;

an octane rating of a fuel; and

a cetane rating of a diesel fuel.

12. The method according to claim 11, further comprising determining at least one of:

a composition of the fuel mixture;

the quality of the fuel for operating an externally-igniting combustion engine; and

the quality of the fuel for operating an a self-igniting combustion engine.