System for controlling fuel injectors

• US 7,647,915 B2
• Filed: 04/23/2007
• Issued: 01/19/2010
• Est. Priority Date: 04/23/2007
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Thor, Todd J.
• Primary Examiner(s): Cronin; Stephen K
• Assistant Examiner(s): Hoang; Johnny H
• Application Number:
  US11/738,939
• Publication Number:
  US 20080257305A1
• Time in Patent Office: 1,002 Days
• Field of Search: 701/104, 701/110, 701/115, 123/480, 123/486
• US Class Current: 123/344
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02D 41/2438 Active learning methods
• CPC Class Codes: F02D 41/2467 for injectors
• CPC Class Codes: F02D 41/40 with means for controlling injection timing or duration
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An injector control system and method for an engine includes a distribution module that calculates a difference between a first average engine speed and a second average engine speed of an engine and a fuel offset module that offsets a learned fuel amount of a first fuel injector of a plurality of fuel injectors based on the difference. The learned fuel amount corresponds to an engine fueling range.

Claims

1. An injector control system for an engine, comprising:

a distribution module that calculates a difference between a first average engine speed and a second average engine speed of an engine;

a fuel offset module that offsets a learned fuel amount of a first fuel injector of a plurality of fuel injectors based on said difference; and

an activation module that enables said control system when said activation module determines that said engine is operating at a steady-state operating point,

wherein said learned fuel amount corresponds to an engine fueling range, and

wherein said activation module determines that said engine is operating at a steady-state condition based on a set of stability conditions that include at least one of an engine coolant temperature exceeding a calibrated engine coolant temperature, a torque output demand on said engine remaining stable for a first period of time, and said control system remaining inactive for a second period of time.

2. An injector control system for an engine, comprising:

a distribution module that calculates a difference between a first average engine speed and a second average engine speed of an engine;

a fuel offset module that offsets a learned fuel amount of a first fuel injector of a plurality of fuel injectors based on said difference; and

wherein said learned fuel amount corresponds to an engine fueling range,

wherein said fuel offset module compares said difference to an engine speed variation value read from an engine speed variation array and said fuel offset module decrements a fueling level value when said difference exceeds said engine speed variation value and increments said fueling level value when said difference is less than said engine speed variation value,

wherein said fuel offset module increments an injector sample value and said fuel offset module adjusts said learned fuel amount when said injector sample value exceeds a sample threshold, and

wherein said fuel offset module subtracts a calibrated fuel amount from said learned fuel amount when said fueling level value falls below a fueling level threshold and said fuel offset module adds said calibrated fuel amount to said learned fuel amount when said fueling level exceeds said fueling level threshold.

3. The control system of claim 2 wherein said fuel offset module adds said learned fuel amount to a desired fueling quantity of said first fuel injector at said engine fueling range.

4. A method for controlling a fuel injector in an engine, comprising:

calculating a difference between a first average engine speed and a second average engine speed of an engine;

offsetting a learned fuel amount of a first fuel injector of a plurality of fuel injectors based on said difference;

enabling said method when said engine operates at a steady-state operating point; and

determining that said engine is operating at a steady-state condition based on a set of stability conditions that include at least one of an engine coolant temperature exceeding a calibrated engine coolant temperature, a torque output demand on said engine remaining stable for a first period of time, and said control system remaining inactive for a second period of time, wherein said learned fuel amount corresponds to an engine fueling range.

5. A method for controlling a fuel injector in an engine, comprising:

calculating a difference between a first average engine speed and a second average engine speed of an engine; and

offsetting a learned fuel amount of a first fuel injector of a plurality of fuel injectors based on said difference;

comparing said difference to an engine speed variation value read from an engine speed variation array and decrementing a fueling level value when said difference exceeds said engine speed variation value and incrementing said fueling level value when said difference is less than said engine speed variation value;

incrementing an injector sample value and adjusting said learned fuel amount when said injector sample value exceeds a sample threshold; and

subtracting a calibrated fuel amount from said learned fuel amount when said fueling level value falls below a fueling level threshold and adding said calibrated fuel amount to said learned fuel amount when said fueling level exceeds said fueling level threshold, wherein said learned fuel amount corresponds to an engine fueling range.

6. The method of claim 5 further comprising adding said learned fuel amount to a desired fueling quantity of said first fuel injector at said engine fueling range.