Feed-forward observer-based control for estimating cylinder air charge

• US 6,718,822 B2
• Filed: 06/07/2002
• Issued: 04/13/2004
• Est. Priority Date: 05/13/2000
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Soliman, Ihab S., Pallett, Tobias John, Robichaux, Jerry D.
• Primary Examiner(s): McCall, Eric S.
• Application Number:
  US10/165,021
• Publication Number:
  US 20030005756A1
• Time in Patent Office: 676 Days
• Field of Search: 731/16, 731/172, 731/173, 731/181, 731/182, 701/101, 701/102, 701/103
• US Class Current: 73/114.32
• CPC Class Codes: F02D 2041/141 using a feed-forward control element
• CPC Class Codes: F02D 2041/1416 Observer
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• 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 41/1401 characterised by the control or regulation method F02D41/1473, F02D41/1477 take precedence
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: G05B 13/04 involving the use of models or simulators
• CPC Class Codes: G05B 17/02 electric

Abstract

A system and method for controlling an internal combustion engine to improve air/fuel ratio control using a feed-forward observer-based control strategy include estimating current and future airflow actuator positions, determining corresponding mass airflow values, and determining a future in-cylinder air charge based on a difference between the current and future mass airflow values. In one embodiment, the difference between current and future mass airflow estimates is used as a feed-forward term and combined with a sensed or measured value generated by a mass airflow sensor prior to being processed using a manifold filling model to predict the future cylinder air charge. In another embodiment, the current and future mass airflow estimates are processed using the manifold filling model with the results used to generate a future delta cylinder air charge that is subsequently used as a feed-forward term and combined with a measured air charge corresponding to a measured mass airflow processed by the manifold filling model.

Claims

1. A method for controlling an internal combustion engine having at least one intake airflow actuator for regulating intake airflow, the method comprising:

predicting current and future positions of the airflow actuator using an actuator model, the current position corresponding to a current, first, engine fuel injection event and the future position corresponding to a subsequent, second, engine intake fuel injection event; and

estimating in-cylinder air charge for the subsequent, second, engine intake fuel injection event based on a difference between the current and future airflow values corresponding to the current and future positions of the airflow actuator, respectively.

2. The method of claim 1 further comprising:

estimating current and future mass airflow values using an airflow model based on the current and future positions of the airflow actuator, respectively;

wherein the difference between the current and future airflow values corresponds to a difference between the current and future mass airflow values.

3. The method of claim 1 further comprising:

estimating current and future mass airflow values using an airflow model based on the current and future positions of the airflow actuator, respectively; and

estimating current and future in-cylinder air charge values corresponding to the current and future mass airflow values, respectively;

wherein the difference between the current and future mass airflow values corresponds to a difference between the current and future air charge values.