Determining engine cylinder contribution from indexed engine data

• US 7,286,927 B2
• Filed: 10/12/2006
• Issued: 10/23/2007
• Est. Priority Date: 05/07/2004
• Status: Expired due to Fees

• Current Assignee: Snap-On Incorporated
• Original Assignee: Snap-On Incorporated
• Inventors: Stoffels, Nicolaas M. J., DeCarlo, Robert D., Mutzabaugh, Dennis M., Meeker, Michael B., Lammers, Ronald M. J.
• Primary Examiner(s): Wolfe; Willis R.
• Assistant Examiner(s): Hoang; Johnny H.
• Application Number:
  US11/546,382
• Publication Number:
  US 20070032939A1
• Time in Patent Office: 376 Days
• Field of Search: 701/100, 701/101, 701/109, 701/114, 701/115, 324378-380, 324/382, 324/392
• US Class Current: 701/114
• CPC Class Codes: G01L 23/085 by measuring fluctuations of starter motor current or of battery voltage battery testing arrangements G01R31/36; testing of electrical installation on transport means G01R31/005; battery testing arrangements G01R31/36
• CPC Class Codes: G01M 15/046 by monitoring revolutions for detecting misfire G01M15/11

Abstract

An engine diagnostic system is provided that enables a service technician to evaluate engine cylinder contribution to output power. The service technician couples one or more signal leads to the vehicle'"'"'s battery, alternator, or accessory receptacle (e.g., cigarette lighter receptacle) to provide an alternator output signal to a signal analyzer. The signal analyzer processes the alternator output signal to generate an engine signature, which represents engine cylinder contribution to engine output power.

Claims

1. A system for processing indexed engine data, the system comprising:

means for calculating a number of indexed engine samples per engine cycle; and

means for constructing an engine cycles signal using the number of indexed engine samples per engine cycle.

2. The system of claim 1, further comprising:

an anti-aliasing filter configured to remove high frequency signal content from the indexed engine data.

3. The system of claim 1, further comprising:

a signature filter configured to remove an unwanted signal component from the engine cycles signal.

4. The system of claim 1, further comprising:

a phase control bias signal configured to control a starting position of the engine cycles signal.

5. The system of claim 1, further comprising:

an external trigger signal configured to control a starting position of the engine cycles signal and to provide the number of indexed engine samples per engine cycle.

6. A method for processing indexed engine data, the method comprising:

calculating a number of indexed engine samples per engine cycle; and

constructing an engine cycles signal using the number of indexed engine samples per engine cycle.

7. The method of claim 6, further comprising:

controlling a starting position of the engine cycles signal with a phase control bias signal.

8. The method of claim 6, further comprising:

controlling a starting position of the engine cycles signal with an external trigger signal.