System and method for processing an accelerometer signal to assist in combustion quality control in an internal combustion engine

• US 7,200,487 B2
• Filed: 11/18/2005
• Issued: 04/03/2007
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Westport Fuel Systems Canada Inc. (Westport Fuel Systems, Inc.)
• Original Assignee: Westport Power Inc. (Westport Fuel Systems, Inc.)
• Inventors: Ancimer, Richard
• Primary Examiner(s): Dolinar; Andrew M.
• Assistant Examiner(s): Hoang; Johnny H.
• Application Number:
  US11/283,156
• Publication Number:
  US 20060106523A1
• Time in Patent Office: 501 Days
• Field of Search: 701/103, 701/105, 701/107, 701/110, 701/111, 701/113, 701/114, 123/479, 123/480, 123/435, 123/501, 123/502, 731/16, 731/19.A, 73/350.3, 73/350.4, 731/172, 731/173, 731/181, 731/15
• US Class Current: 701/111
• CPC Class Codes: G01L 23/225 circuit arrangements therefor

Abstract

A method for processing an accelerometer signal associated with the combustion process in an operating internal combustion engine, the method comprising the steps of measuring an accelerometer signal across a window of selected crank angle degrees during a cycle of the engine, the measured accelerometer signal including a combustion acceleration component and a motored acceleration components; and applying a shape function to the measured accelerometer signal to reduce the motored acceleration component.

Claims

1. A method for processing an accelerometer signal associated with the combustion process in an operating internal combustion engine, the method comprising the steps of:

a) measuring an accelerometer signal across a window of selected crank angle degrees during a cycle of said engine, the measured accelerometer signal including a combustion acceleration component and a motored acceleration components; and

b) applying a shape function to said measured accelerometer signal to reduce said motored acceleration component.

2. A method as defined in claim 1, including a preprocessing step selected from one of:

a) pivoting said shape function prior to said applying step;

b) in said applying step, determining a difference signal between said measured accelerometer signal and said shape function and reflecting a portion of said difference signal about a predetermined crank angle to extract said combustion component;

c) in said applying step, determining a difference signal between said measured accelerometer signal and said shape function and differentiating said difference signal to extract said combustion component.

3. A method as defined in claim 2, including a step of applying a phase shift to said shape function prior to said preprocessing step.