MASS AIR FLOW ESTIMATION BASED ON MANIFOLD ABSOLUTE PRESSURE

• US 20060069490A1
• Filed: 09/29/2004
• Published: 03/30/2006
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Buslepp, Kenneth J., Mladenovic, Ljubisa M., Trombley, Douglas E.
• Granted Patent: US 7,027,905 B1
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0408 Estimation of intake manifold pressure
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: G01F 1/34 by measuring pressure or differential pressure
• CPC Class Codes: G01F 1/86 Indirect mass flowmeters, e.g. measuring volume flow and density, temperature or pressure

Abstract

A control system that determines a mass air flow through a throttle of an internal combustion engine (ICE) having an intake manifold includes a calculator that calculates an estimated mass air flow based on a throttle position and an adjustment module that determines an adjustment value. The adjustment value is based on the estimated mass air flow, an estimated manifold absolute pressure and a measured manifold absolute pressure. A multiplier multiplies the estimated mass air flow by the adjustment value to determine the mass air flow.

Claims

1. A control system that determines a mass air flow through a throttle of an internal combustion engine (ICE) having an intake manifold, comprising:

a calculator that calculates an estimated mass air flow based on a throttle position;

an adjustment module that determines an adjustment value based on said estimated mass air flow, an estimated manifold absolute pressure and a measured manifold absolute pressure; and

a multiplier that multiplies said estimated mass air flow by said adjustment value to determine said mass air flow.

2. The control system of claim 1 further comprising a calculator that calculates said estimated manifold absolute pressure.

3. The control system of claim 1 further comprising:

an engine speed sensor that generates an engine speed signal; and

an intake manifold temperature sensor that generates an intake manifold temperature signal, wherein said estimated manifold absolute pressure is based on said engine speed signal and said intake manifold temperature signal.

4. The control system of claim 1 further comprising a multiplier that calculates an adjustment input as a product of said estimated mass air flow and a manifold absolute pressure error.

5. The control system of claim 4 wherein said manifold absolute pressure error is determined as a difference between said estimated manifold absolute pressure and said measured manifold absolute pressure.

6. The control system of claim 1 wherein said adaptation module is an integrator that integrates an adjustment input that is based on said estimated mass air flow and a manifold absolute pressure error.

7. The control system of claim 6 wherein said adaptation module integrates said adjustment input and multiplies said adjustment input by a gain.

8. (canceled)

11. A vehicle having a throttle that regulates a mass air flow into an intake manifold of an engine, comprising:

a throttle position sensor that monitors a position of said throttle and that generates a throttle position signal; and

a controller that calculates an estimated mass air flow based on said throttle position signal, that calculates said mass air flow based on said estimated mass air flow and an adjustment value, wherein said adjustment value is based on a manifold absolute pressure error and said estimated mass air flow, and operates said vehicle based on said mass air flow.

9. The vehicle of claim 11 wherein said controller calculates said mass air flow based on an estimated manifold absolute pressure.

10. The vehicle of claim 11 wherein said estimated manifold absolute pressure is further based on a previous value of said mass air flow, a volumetric efficiency of said engine, a volume of said intake manifold and a temperature of said intake manifold.

12. The vehicle of claim 11 wherein said controller calculates said manifold absolute pressure error as a difference between said estimated manifold absolute pressure and a measured manifold absolute pressure.

13. The vehicle of claim 12 further comprising a manifold absolute pressure sensor that generates a measured manifold absolute pressure signal.

14. The vehicle of claim 11 wherein said controller calculates a product of said manifold absolute pressure error and said estimated mass air flow and integrates said product over time to determine said adjustment value.

15. The vehicle of claim 14 wherein said controller of multiplies said product by a gain.

16. A method of determining a mass air flow into an intake manifold of an engine, comprising:

calculating an estimated mass air flow based on a throttle area;

determining an adjustment value based on said estimated mass air flow, an estimated manifold absolute pressure and a measured manifold absolute pressure; and

calculating said mass air flow based on said estimated mass air flow and said adjustment value.

17. The method of claim 16 further comprising controlling said engine based on said mass air flow.

18. The method of claim 16 wherein said estimated manifold absolute pressure is based on a previous value of said mass air flow.

19. The method of claim 18 wherein said estimated manifold absolute pressure is further based on a volumetric efficiency of said engine, a volume of said intake manifold and a temperature of said intake manifold.

20. The method of claim 17 wherein said adjustment value is based on a manifold absolute pressure error and said estimated mass air flow.

21. The method of claim 20 further comprising calculating said manifold absolute pressure error as a difference between said estimated manifold absolute pressure and a measured manifold absolute pressure.

22. The method of claim 21 further comprising generating a measured manifold absolute pressure signal using a manifold absolute pressure sensor.

23. The method of claim 20 further comprising:

calculating a product of said manifold absolute pressure error and said estimated mass air flow; and

integrating said product overtime to determine said adjustment value.

24. The method of claim 23 further comprising multiplying said product by a gain.

25. The method of claim 16 further comprising determining said throttle area based on a throttle position.

26. The method of claim 16 further comprising comparing said mass air flow to a mass air flow value determined based on a mass air flow signal.