MANIFOLD PRESSURE AND AIR CHARGE MODEL

• US 20140251282A1
• Filed: 03/11/2013
• Published: 09/11/2014
• Est. Priority Date: 03/11/2013
• Status: Active Grant

• Current Assignee: Tula Technology, Incorporated (BorgWarner Incorporated)
• Original Assignee: Tula Technology, Incorporated (BorgWarner Incorporated)
• Inventors: KOTWICKI, Allan J., VAN ESS, Joel D.
• Granted Patent: US 9,945,313 B2
• Time in Patent Office: Days
• US Class Current: 123/481
• 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 2200/0408 Estimation of intake manifold pressure
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• CPC Class Codes: F02D 41/18 by measuring intake air flow

Abstract

In one aspect, an engine controller for an engine including multiple working chambers is described. The engine controller includes a mass air charge determining unit that estimates a mass air charge or amount of air to be delivered to a working chamber. Firing decisions made for a firing window of one or more firing opportunities are used to help determine the mass air charge. The engine controller also includes a firing controller, which is arranged to direct firings to deliver a desired output. Fuel is delivered to a working chamber based on the estimated mass air charge.

Claims

1. An engine controller for an internal combustion engine having a plurality of working chambers, the engine controller comprising:

a mass air charge determining unit that estimates a mass air charge wherein a firing frequency is used to determine the estimated mass air charge; and

a firing controller arranged to direct firings that delivers a desired engine output wherein fuel is delivered to a working chamber based on the estimated mass air charge.

2. An engine controller as recited in claim 1 wherein:

the internal combustion engine has an intake manifold and

a measurement of air flow into the intake manifold is used to determine the estimated mass air charge.

3. An engine controller as recited in claim 1 wherein:

the firing frequency is determined by the number of firing events in a firing window of one or more firing opportunities.

4. An engine controller as recited in claim 3 wherein the estimated manifold absolute pressure is based on a determination that a skip in the firing window tends to contribute to a rise in the estimated manifold absolute pressure.

5. An engine controller as recited in claim 1 wherein:

the mass air charge determining unit estimates a manifold absolute pressure; and

the estimated mass air charge is calculated using the estimated manifold absolute pressure.

6. An engine controller as recited in claim 5 wherein:

the estimated manifold absolute pressure is based on at least one selected from the group consisting of the intake valve opening and closing timing, the engine speed, and the manifold air temperature; and

the estimated mass air charge is calculated using the estimated manifold absolute pressure.

7. An engine controller as recited in claim 5 wherein the estimated mass air charge is calculated without input from a sensor that directly reads the pressure within an intake manifold.

8. An engine controller as recited in claim 1 wherein the estimated mass air charge is calculated on a firing opportunity by firing opportunity basis.

9. An engine controller as recited in claim 1 wherein the firing controller is arranged to direct firings in a skip fire manner such that at least one selected working cycle of at least one selected working chamber is deactivated and at least one selected working cycle of at least one selected working chamber is fired wherein individual working chambers are sometimes deactivated and sometimes fired.

10. An engine controller as recited in claim 1 wherein a firing window is used to help determine the firing frequency and the mass air charge, the firing window including one or more firing opportunities, each firing opportunity involving a skip or a fire, wherein a skip and a fire each have a different effect on a calculation of the estimated mass air charge.

11. An engine controller as recited in claim 1 wherein the mass air flow estimation unit is arranged to:

calculate a first amount of air that comes into the intake manifold based on input from a mass air flow sensor; and

calculate a second amount of air that goes out of the intake manifold based on a determination of the number of skips or fires in a firing window wherein the firing window involves one or more firing opportunities;

calculate an estimated manifold absolute pressure based on the first and second calculated amounts of air; and

calculate the estimated mass air charge based on the estimated manifold absolute pressure.

12. An engine controller as recited in claim 1 wherein the working chambers are individually controlled and a firing decision is made for each individual working chamber in real time.

13. An engine controller for an internal combustion engine having a plurality of working chambers, the engine controller comprising:

a mass air charge determining unit that estimates a mass air charge wherein firing decisions made for a firing window of one or more firing opportunities are used to determine the estimated mass air charge; and

a firing controller arranged to direct firings that delivers a desired output wherein fuel is delivered to a working chamber based on the estimated mass air charge.

14. An engine controller as recited in claim 13 wherein:

the mass air charge determining unit estimates a manifold absolute pressure; and

the estimated mass air charge is calculated using the estimated manifold absolute pressure.

15. An engine controller as recited in claim 13 wherein the estimated mass air charge is calculated without input from a sensor that directly reads the pressure within an intake manifold.

16. An engine controller as recited in claim 13 wherein the estimated manifold absolute pressure is based on a determination that a skip in the firing window tends to contribute to a rise in the estimated manifold absolute pressure.

17. A method for control of an internal combustion engine comprising:

measuring an air mass flow input into an intake manifold;

calculating a firing frequency;

determining an intake valve timing;

determining an exhaust valve timing;

sensing an engine speed;

determining a manifold air temperature; and

calculating a mass air charge based at least on the air mass flow, the firing frequency, the cam angle, the engine speed, and the manifold air temperature.

18. A method as recited in claim 17 wherein calculating a firing frequency comprises determining the number of firings over an interval of firing opportunities.

19. A method as recited in claim 17 wherein a cam position is used to determine the intake valve timing and the exhaust valve timing.

20. A method as recited in claim 17 wherein an estimated manifold absolute pressure is determined as part of the mass air charge calculation.