Method for controlling throttle air velocity during throttle position changes

• US 6,701,890 B1
• Filed: 12/06/2001
• Issued: 03/09/2004
• Est. Priority Date: 12/06/2001
• Status: Active Grant

• Current Assignee: Woodward Governor Company
• Original Assignee: Brunswick Corporation
• Inventors: Suhre, Blake R., Haddad, Robert E.
• Primary Examiner(s): Gimie, Mahmoud
• Assistant Examiner(s): Huynh, Hai
• Application Number:
  US10/011,924
• Time in Patent Office: 824 Days
• Field of Search: 123/399, 123/361, 123/403, 123/350, 731/182
• US Class Current: 123/350
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 41/18 by measuring intake air flow

Abstract

An engine control system calculates air velocity through a throttle body as a function of mass air flow through the throttle body, air density, and the effective area of air flow through the throttle body as a function of throttle plate position. Mass air flow is calculated as a function of the effective area through the throttle body, barometric pressure, manifold pressure, manifold temperature, the ideal gas constant, and the ratio of specific heats for air. By controlling the throttle plate position as a dual function of throttle demand, which is a manual input, and air velocity through the throttle body, certain disadvantages transient behavior of the engine can be avoided.

Claims

1. A method for controlling the operation of an engine, comprising the steps of:

receiving a throttle command signal;

determining a commanded throttle position as a function of said throttle command signal;

determining a mass air flow through a preselected portion of an air intake conduit of said engine;

determining a density of air passing through said preselected portion of an air intake conduit of said engine;

determining an effective area of said preselected portion of an air intake conduit of said engine;

determining an air flow velocity through said preselected portion of an air intake conduit of said engine;

comparing said air flow velocity to an acceptable range of velocities; and

providing an amended throttle command signal in response to said air flow velocity not being within said acceptable range of velocities.

2. The method of claim 1, wherein:

said commanded throttle position is a percentage of full travel of a throttle relative to a throttle body.

3. The method of claim 1, wherein:

said mass air flow determining step comprises the step of measuring said mass air flow with a mass air flow sensor.

4. The method of claim 1, wherein:

said mass air flow determining step comprises the step of calculating said mass air flow as a function of barometric pressure, manifold pressure, temperature, and said effective area of said preselected portion of an air intake conduit of said engine.

5. The method of claim 1, wherein:

said air density determining step comprises the steps of measuring a temperature at said preselected portion of an air intake conduit of said engine, measuring a pressure at said preselected portion of an air intake conduit of said engine, and calculating said air density as a function of said pressure and temperature.

6. The method of claim 1, wherein:

said effective area determining step comprises the steps of selecting said effective area from a table of a plurality of magnitudes of said effective area stored as a function of an associated plurality of throttle positions.

7. The method of claim 1, wherein:

said air flow velocity determining step comprises the step of calculating said air flow velocity as a function of said mass air flow through a preselected portion of an air intake conduit of said engine, said density of air passing through said preselected portion of an air intake conduit of said engine, and a temperature of air within an air manifold of said engine.

8. The method of claim 1, wherein:

said throttle command signal receiving step comprised the step of receiving a signal which represents the position of a manually movable throttle control handle.

9. A method for controlling the operation of an engine, comprising the steps of:

receiving a throttle command signal; and

causing a throttle plate to move to a position determined as a dual function of said throttle command position and an air velocity through a preselected portion of an air intake conduit of said engine;

wherein said causing step comprises the steps of;

a) determining a commanded throttle position as a function of said throttle command signal;

b) determining a mass air flow through a preselected portion of an air intake conduit of said engine;

c) determining a density of air passing through said preselected portion of an air intake conduit of said engine;

d) determining an effective area of said preselected portion of an air intake conduit of said engine;

e) determining said air flow velocity through said preselected portion of an air intake conduit of said engine;

f) comparing said air flow velocity to an acceptable range of velocities; and

g) providing an amended throttle command signal in response to said air flow velocity not being within said acceptable range of velocities.

10. The method of claim 9, wherein:

said throttle command signal receiving step comprised the step of receiving a signal which represents the position of a manually movable throttle control handle.

11. The method of claim 9, wherein:

said commanded throttle position is a percentage of full travel of a throttle relative to a throttle body.

12. The method of claim 9, wherein:

said mass air flow determining step comprises the step of measuring said mass air flow with a mass air flow sensor.

13. The method of claim 9, wherein:

said mass air flow determining step comprises the step of calculating said mass air flow as a function of barometric pressure, manifold pressure, temperature, and said effective area of said preselected portion of an air intake conduit of said engine.

14. The method of claim 9, wherein:

said air density determining step comprises the steps of measuring a temperature at said preselected portion of an air intake conduit of said engine, measuring a pressure at said preselected portion of an air intake conduit of said engine, and calculating said air density as a function of said pressure and temperature.

15. The method of claim 9, wherein:

said effective area determining step comprises the steps of selecting said effective area from a table of a plurality of magnitudes of said effective area stored as a function of an associated plurality of throttle positions.

16. The method of claim 9, wherein:

said air flow velocity determining step comprises the step of calculating said air flow velocity as a function of said mass air flow through a preselected portion of an air intake conduit of said engine, said density of air passing through said preselected portion of an air intake conduit of said engine, and a temperature of air within an air manifold of said engine.

17. The method of claim 9, wherein:

said throttle command signal receiving step comprised the step of receiving a signal which represents the position of a manually movable throttle control handle.

18. A method for controlling the operation of an engine, comprising the steps of:

receiving a throttle command signal;

determining an air flow velocity through said preselected portion of an air intake conduit of said engine; and

causing a throttle plate to move to a position determined as a dual function of said throttle command position and said air velocity through a preselected portion of an air intake conduit of said engine;

wherein said throttle command signal receiving step comprises the step of receiving a signal which represents the position of a manually movable throttle control handle;

said causing step comprises the steps of;

a) determining a commanded throttle position as a function of said throttle command signal;

b) determining a mass air flow through a preselected portion of an air intake conduit of said engine;

c) determining a density of air passing through said preselected portion of an air intake conduit of said engine;

d) determining an effective area of said preselected portion of an air intake conduit of said engine;

f) comparing said air flow velocity to an acceptable range of velocities; and

g) providing an amended throttle command signal in response to said air flow velocity not being within said acceptable range of velocities.

19. The method of claim 18, wherein:

said commanded throttle position is a percentage of full travel of a throttle relative to a throttle body.

20. The method of claim 19, wherein:

said mass air flow determining step comprises the step of measuring said mass air flow with a mass air flow sensor.

21. The method of claim 20, wherein:

said mass air flow determining step comprises the step of calculating said mass air flow as a function of barometric pressure, manifold pressure, temperature, and said effective area of said preselected portion of an air intake conduit of said engine.

22. The method of claim 21, wherein:

said air density determining step comprises the steps of measuring a temperature at said preselected portion of an air intake conduit of said engine, measuring a pressure at said preselected portion of an air intake conduit of said engine, and calculating said air density as a function of said pressure and temperature.

23. The method of claim 22, wherein:

said effective area determining step comprises the steps of selecting said effective area from a table of a plurality of magnitudes of said effective area stored as a function of an associated plurality of throttle positions.

24. The method of claim 23, wherein:

said air flow velocity determining step comprises the step of calculating said air flow velocity as a function of said mass air flow through a preselected portion of an air intake conduit of said engine, said density of air passing through said preselected portion of an air intake conduit of said engine, and a temperature of air within an air manifold of said engine.

25. The method of claim 24, wherein:

said throttle command signal receiving step comprised the step of receiving a signal which represents the position of a manually movable throttle control handle.