Method of estimating soot output from an engine

Patent metadata

Field	Value
Publication number	US-9689778-B2
Application number	US-201414168485-A
Country	US
Kind code	B2
Filing date	Jan 30, 2014
Priority date	Jan 30, 2014
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A method of estimating a current soot output from an engine includes sensing a mass flow rate of a flow of exhaust gas from the engine, and defining a soot output base rate of the engine when the engine is operating at a reference state. A soot ratio for a current operating state of the engine is calculated. The mass flow rate, the soot output base rate, and the soot ratio are multiplied together to define an estimated value of the current soot output from the engine. The soot ratio is based on current engine operating parameters, including an air/fuel ratio of the engine, an exhaust gas recirculation ratio of the engine, a fuel injection pressure of the engine, and a fuel injection timing of the engine.

First claim

The invention claimed is:

1. A method of estimating a current soot output from an engine, the method comprising:
sensing a mass flow rate of a flow of exhaust gas from the engine;
defining a soot output base rate of the engine, with a controller, when the engine is operating at a reference state;
calculating a soot ratio for a current operating state of the engine, with a controller;
multiplying the mass flow rate, the soot output base rate, and the soot ratio together to define an estimated value of the current soot output from the engine; and
controlling an exhaust gas treatment system connected to the engine, with the controller, based upon the estimated value of the current soot output from the engine;
wherein the soot ratio is calculated from the equation:
sootratio= e ((AFRpor)+(EGRpor)+(InjPpor)+(InjTpor)) ;

wherein AFRpor is an air/fuel ratio portion of the soot ratio, EGRpor is an exhaust gas recirculation portion of the soot ratio, InjPpor is a fuel injection pressure portion of the soot ratio, and InjTpor is a fuel injection timing portion of the soot ratio;
wherein the air/fuel ratio portion is calculated from the equation:
AFRpor=[( a AFR )(AFR)+(ƒ AFR )][AFR)−(AFR base )];

wherein AFR is an air/fuel ratio of the engine at the current operating state, a AFR is an AFR term coefficient for the air/fuel ratio, ƒ AFR is a functional timing value of the air/fuel ratio, and AFR base is an air/fuel ratio base value of the engine when the engine is operating at the reference state;
wherein the exhaust gas recirculation portion is calculated from the equation:
EGRpor=[( a EGR )(EGR)+(ƒ EGR )][(EFR)−(EGR base )];

wherein EGR is an exhaust gas recirculation ratio of the engine at the current operating state, a EGR is an EGR term coefficient for the exhaust gas recirculation ratio, ƒ EGR is a functional timing value of the exhaust gas recirculation ratio, and EGR base is an exhaust gas recirculation base ratio of the engine when the engine is operating at the reference state;
wherein the fuel injection pressure portion is calculated from the equation:
Inj P por=[( a InjP )(AFR)+(ƒ InjP )][(Inj P )−(Inj P base )];

wherein AFR is the air/fuel ratio of the engine at the current operating state, InjP is a fuel injection pressure of the engine at the current operating state, a InjP is an InjP term coefficient for the air/fuel ratio, ƒ InjP is a functional timing value of the fuel injection pressure of the engine, and InjP base is a fuel injection pressure base value of the engine when the engine is operating at the reference state; and
wherein the fuel injection timing portion is calculated from the equation:
Inj T por=(ƒ InjT )[(Inj T )−(Inj T base )];

wherein InjT is a fuel injection timing of the engine at the current operating state, ƒ InjT is a functional value of the fuel injection timing of the engine, and InjT base is a fuel injection timing base value of the engine when the engine is operating at the reference state.

2. The method set forth in claim 1 wherein defining the soot output base rate of the engine when the engine is operating at the reference state includes referencing a table to determine the soot output base rate based upon a rotational speed of the engine and a fueling rate of the engine at the current operating state.

3. The method set forth in claim 1 further comprising sensing the air/fuel ratio of the engine at the current operating state, sensing the exhaust gas recirculation ratio of the engine at the current operating state, sensing the fuel injection timing of the engine at the current operating state, sensing the fuel injection pressure of the engine at the current operating state, sensing a rotational speed of the engine at the current operating state, and sensing a fueling rate of the engine at the current operating state.

4. The method set forth in claim 3 further comprising referencing a table to determine the AFR term coefficient used to calculate the air/fuel ratio portion of the soot ratio, based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state.

5. The method set forth in claim 4 further comprising referencing a table to determine the air/fuel ratio base value used to calculate the air/fuel ratio portion of the soot ratio, based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state.

6. The method set forth in claim 5 further comprising determining the functional timing value of the air/fuel ratio based upon the rotational speed of the engine at the current operating state, the fueling rate of the engine at the current operating state, and the fuel injection timing of the engine at the current operating state.

7. The method set forth in claim 6 wherein determining the functional timing value of the air/fuel ratio includes calculating the functional timing value of the air/fuel ratio from the equation:
ƒ AFR =b 2 (ƒ(( b 1 )(Inj T )))+ b 3

wherein b 1 is a coefficient for the functional timing value of the air/fuel ratio determined from a table based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state;
wherein b 2 is a coefficient of the fuel injection timing of the engine determined from a table based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state;
wherein b 3 is an adjustment value of the functional timing value of the air/fuel ratio determined from a table based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state; and
wherein ƒ((b 1 )(InjT)) is determined from a table based upon the product of the coefficient b 1 for the functional timing value of the air/fuel ratio and the fuel injection timing of the engine at the current operating state.

8. The method set forth in claim 3 further comprising referencing a table to determine the EGR term coefficient used to calculate the exhaust gas recirculation portion of the soot ratio, based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state.

9. The method set forth in claim 8 further comprising referencing a table to determine the exhaust gas recirculation base ratio used to calculate the exhaust gas recirculation portion of the soot ratio, based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state.

10. The method set forth in claim 9 further comprising determining the functional timing value of the exhaust gas recirculation ratio based upon the rotational speed of the engine at the current operating state, the fueling rate of the engine at the current operating state, and the fuel injection timing of the engine at the current operating state.

11. The method set forth in claim 10 wherein determining the functional timing value of the exhaust gas recirculation rate includes calculating the functional timing value of the exhaust gas recirculation rate from the equation:
ƒ EGR =b 2 (ƒ(( b 1 )(Inj T )))+ b 3

wherein b 1 is a coefficient for the functional timing value of the exhaust gas recirculation ratio determined from a table based upon the rotational speed of the engine at the current operating state, and the fueling rate of the engine at the current operating state;
wherein b 2 is a coe

Assignees

• Gm Global Tech Operations Llc

Inventors

• Sun Min
• Ardanese Michelangelo
• Bilancia Michele
• Sticchi Giorgio

Classifications

• G01M15/102 Primary

  by monitoring exhaust gases · CPC title

• G01N33/0036

  specially adapted to detect a particular component (physical analysis of gaseous biological material G01N33/497) · CPC title

• Y02A50/20

  Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters · CPC title