Method for detecting a power loss condition of a reciprocating internal combustion engine

• US 6,082,187 A
• Filed: 12/18/1998
• Issued: 07/04/2000
• Est. Priority Date: 12/18/1998
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Schricker, David R., Zavarehi, Masoud K.
• Primary Examiner(s): Solis, Erick R.
• Application Number:
  US09/216,597
• Time in Patent Office: 564 Days
• Field of Search: 123/436, 73/116, 73/117.3, 73/494, 701/110
• US Class Current: 73/114.13
• CPC Class Codes: G01M 15/00 Testing of engines

Abstract

A method for detecting a power loss condition of an internal combustion engine, the engine having at least one cylinder and a crank shaft, the method including the steps of sensing rotational crank shaft speed for a plurality of designated crank shaft rotational positions over a predetermined number of cycles of rotation, determining an average crank shaft speed fluctuation for each crank shaft position, determining information representative of crank shaft kinetic energy variation due to each firing event in the cylinder, and determining information representative of an average fuel flow rate. Information representative of a power loss for the cylinder is determined as a function of the crank shaft kinetic energy variation, average crank shaft speed and average fuel flow rate and a representative power loss signal is responsively produced.

Claims

1. A method for detecting a power loss condition of a reciprocating internal combustion engine, the engine having at least one cylinder and a rotating crank shaft, comprising the steps of:

sensing rotational crank shaft speed for a plurality of designated crank shaft rotational positions over a predetermined number of cycles of rotation for each crank shaft position;

determining an average crank shaft speed fluctuation for each crank shaft position;

determining information representative of crank shaft kinetic energy variation due to each firing event in the cylinder;

determining information representative of an average fuel flow rate; and

determining information representative of a power loss for the cylinder as a function of crank shaft kinetic energy variation, average crank shaft speed and average fuel flow rate and responsively producing a representative power loss signal.

2. The method, as set forth in claim 1, further including the step of determining a normalized kinetic energy variation for the cylinder, wherein information representative of a power loss for the cylinder is determined as a function of the normalized kinetic energy variation, average crank shaft speed and average fuel flow rate.

3. The method, as set forth in claim 1, wherein the designated plurality of crank shaft positions comprise crank shaft positions within a predetermined range of crank shaft positions before and after a top dead center position for the cylinder.

4. The method, as set forth in claim 3, wherein the predetermined range comprises a range of from about 60°

before the top dead center position to about 60°

after the top dead center position.

5. The method, as set forth in claim 1, wherein the step of determining the power loss is performed using a neural network.

6. The method, as set forth in claim 5, wherein the step of determining the power loss is performed using a radial basis neural network.