Method and system of diesel engine setpoint compensation for transient operation of a heavy duty diesel engine

• US 7,281,518 B1
• Filed: 03/15/2007
• Issued: 10/16/2007
• Est. Priority Date: 03/15/2007
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Original Assignee: Detroit Diesel Corporation (Daimler Truck Holding AG)
• Inventors: Allain, Marc Christian, Sun, Min
• Primary Examiner(s): Kwon, John T.
• Application Number:
  US11/724,509
• Time in Patent Office: 215 Days
• Field of Search: 123/434, 123/435, 123/446, 123/478, 123/480, 123/305, 123/382, 123/463, 123/568.14, 123/568.2, 123/568.12, 701/103, 701/104, 701/105, 701/108
• US Class Current: 123/434
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 3/0253 adding fuel to exhaust gases
• CPC Class Codes: F01N 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/103 Oxidation catalysts for HC and CO only
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 37/24 by using pumps or turbines with adjustable guide vanes
• CPC Class Codes: F02D 13/04 using engine as brake
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/107 and deceleration
• CPC Class Codes: F02D 41/1405 Neural network control
• CPC Class Codes: F02D 41/1462 with determination means using an estimation
• CPC Class Codes: F02D 41/1467 with determination means using an estimation
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/25 with coolers having bypasses
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Method for controlling and improving the transient emissions of an electronically controlled heavy duty diesel engine having an ECM with memory, a turbocharger and an EGR system.

Claims

1. A method to improve transient emission control in an electronically controlled heavy duty diesel engine equipped with a fuel system and an air system having an EGR, and a memory within an Engine Control Module (ECM) comprising:

determining a required transient air fuel ratio;

determining a difference in air fuel ratio (setpoint minus actual), AFR;

determining a change in EGR setpoint (Δ

EGR) to compensate for air system response;

determining a transient EGR setpoint;

determining a final EGR setpoint;

determining a required transient fuel system pressure setpoint;

determining a difference in fuel system pressure (setpoint minus actual), FDP;

determining a change in beginning of injection (Δ

BOI);

determining a transient beginning of injection setpoint;

determining a final beginning of injection setpoint;

implementing the final EGR setpoint to compensate for the air system reaction time during transient engine operation and implementing the final BOI to compensate for the fuel system reaction times during transient engine operation to improve engine operation and reduce emissions.

2. The method of claim 1, wherein determining said transient air fuel ratio setpoint is made using an air fuel ratio setpoint model derived from engine emission targets and fuel economy targets stored within memory.

3. The method of claim 1, wherein determining said required air fuel ratio setpoint I made by comparing the required transient air fuel ratio setpoint with an actual air fuel ratio setpoint to compute the difference between the required transient air fuel ratio and the actual air fuel ratio Δ

Air Fuel Ratio (Δ

AFR).

4. The method of claim 1, wherein multiplying Δ

AFR by Δ

target engine emission/Δ

AFR and dividing said sum by Δ

target engine emission/Δ

EGR to calculate the change in EGR (Δ

EGR) setpoint necessary to compensate for the air system response.

5. The method of claim 1, wherein determining said transient EGR setpoint is made from an EGR setpoint model using engine emission targets and fuel economy targets.

6. The method of claim 1, wherein determining said final EGR setpoint is made by adding the Δ

EGR and the transient EGR setpoint.

7. The method of claim 1, wherein determining the transient fuel system pressure setpoint is made by a fuel system pressure setpoint model using engine emission targets and fuel economy targets.

8. The method of claim 1, wherein determining said Δ

BOI is made by calculating a partial derivative of at least one target engine emission with respect to common rail pressure (Δ

target emission/Δ

fuel system delivery pressure (Δ

FDP));

calculating a partial derivative of at least one target engine emission with respect to beginning of injection (Δ

target engine emission/Δ

BOI); and

multiplying the Δ

P_rail by Δ

target emission/Δ

FDP and dividing said sum by Δ

target emission/Δ

BOI to calculate a required change in beginning of injection (Δ

BOI).

9. The method of claim 1, wherein determining said transient beginning of injection setpoint is made from a model using engine emission targets and fuel economy targets.

10. A method to improve transient emission control in an electronically controlled heavy duty diesel engine equipped with a common rail fuel system and an air system having an EGR system, and a memory within an Engine Control Module (ECM), comprising:

estimating a required transient air-fuel ratio setpoint from an air-fuel ratio setpoint model using engine emission targets and fuel economy targets;

comparing said required transient air-fuel ratio setpoint with an actual air fuel ratio to compute a difference between the required transient air fuel ratio and the actual air fuel ratio as Δ

Air Fuel Ratio (Δ

AFR);

calculating a partial derivative of at least on target engine emission with respect to Air Fuel Ratio (Δ

target engine emission/Δ

AFR);

calculating a partial derivative of at least one target engine emission with respect to EGR (Δ

target engine emission/Δ

EGR);

multiplying Δ

AFR by Δ

target engine emission/Δ

AFR and dividing said product by Δ

target engine emission/Δ

EGR to calculate the change in EGR (Δ

EGR) setpoint necessary to compensate for the air system response;

estimating a transient EGR setpoint from an EGR setpoint model using engine emission targets and fuel economy targets;

calculating a final EGR setpoint by adding the Δ

EGR and the transient EGR setpoint;

estimating a required transient common rail pressure setpoint from a common rail pressure setpoint model using engine emission targets and fuel economy targets;

comparing said transient common rail pressure with an actual common rail pressure and computing a difference between the transient common rail pressure and the actual common rail pressure as Δ

P_rail;

calculating a partial derivative of at least one target engine emission with respect to common rail pressure (Δ

target emission/Δ

P_rail);

calculating a partial derivative of at least one target engine emission with respect to beginning of injection (Δ

target engine emission/Δ

BOI);

multiplying the Δ

P rail by Δ

target emission/Δ

P_rail and dividing said product by Δ

target emission/Δ

BOI to calculate the change in beginning of injection (Δ

BOI);

estimating a transient beginning of injection setpoint from a beginning of injection setpoint model using engine emission targets and fuel economy targets;

calculating a final beginning of injection setpoint (Final BOI) by adding the Δ

BOI and the transient beginning of injection setpoint;

implementing the final EGR setpoint to compensate for the air system reaction time during transient engine operation and implementing the final BOI to compensate for the fuel system reaction times during transient engine operation to improve engine operation and reduce emissions.

11. The method of claim 10, wherein said engine emission targets are NOx, HC, BSFC and CO targets.

12. The method of claim 10, wherein said engine measured operating conditions are engine RPM and engine Load.

13. The method of claim 10, wherein said Air Fuel Ratio Setpoint model is neural network based.

14. The method of claim 10, wherein said Air Fuel Ratio Setpoint is table based within the memory of the ECM.

15. The method of claim 10, wherein said Pressure rail setpoint model is neural network based.

16. The method of claim 10, wherein said Pressure Rail Setpoint Model is table based within the memory of the ECM.

17. The method of claim 10, wherein said EGR setpoint Model is neural network based.

18. The method of claim 10, wherein said EGR Setpoint Model is table based within the memory of the ECM.

19. The method of claim 10, wherein said beginning of injection setpoint model is neural network based.

20. The method of claim 11, wherein said beginning of injection setpoint model is table based within the memory of the ECM.