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US5495415A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and system for detecting a misfire of a reciprocating internal combustion engine

Assignee: University of Michigan (System)
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Filing: 1993-11-18
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Granted: 1996-02-27
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Expires: 2013-11-18
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Abstract

Abstract A trainable, pattern recognition-based method and system for detecting misfire in a reciprocating internal combustion engine having an engine cycle frequency in the frequency domain from crankshaft angular velocity. Preferably, a pattern recognition system including a neural network is utilized. Crankshaft angular position is sensed to develop an electrical signal which is a function of the crankshaft angular velocity. The electrical signal contains data which is sampled. The sampled data is transformed to an equivalent frequency domain spectrum including frequency components of the engine cycle frequency and harmonics thereof. A load signal such as mass airflow and an RPM signal are generated. The magnitudes and phases of the frequency components and the load and RPM signals are supplied to the neural network to distinguish between a true misfire and normal cyclic variability which characterizes the combustion process.

Inventors

  • 👤 William B. Ribbens
  • 👤 Jaehong Park
  • 👤 Giorgio Rizzoni

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 09:55
CPC Classifications
G; G01; G01M; G01M15/00; G01M15/04; G01M15/11; F; F02; F02D; F02D2200/00; F02D2200/02; F02D2200/10; F02D2200/1015; F02D41/00; F02D41/02; F02D41/14; F02D41/1401; F02D41/1405

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 162 words
A method for detecting a misfire of a reciprocating internal combustion engine with a trainable pattern recognition system, the engine including a plurality of reciprocating components having an engine cycle frequency, at least one cylinder and a crankshaft, the method comprising the steps of: generating an electrical signal as a function of crankshaft angular velocity, the electrical signal containing data; sampling the data synchronously with crankshaft angular position at a sampling rate to obtain sampled data; transforming the sampled data to an equivalent frequency domain spectrum, including frequency components having complex amplitudes at the engine cycle frequency and harmonics thereof; and applying an algorithm to the frequency components, which algorithm distinguishes between a true misfire and normal cyclic variability which characterizes the combustion process in each cylinder of the engine to thereby obtain a misfire signal, the step of applying the algorithm including the step of inputting the frequency components as input vectors to the pattern recognition system to identify the misfire.
Claim 2
Independent Claim 162 words
A method for detecting a misfire of a reciprocating internal combustion engine with a trainable pattern recognition system, the engine including a plurality of reciprocating components having an engine cycle frequency, at least one cylinder and a crankshaft, the method comprising the steps of: generating an electrical signal as a function of crankshaft angular velocity, the electrical signal containing data; sampling the data synchronously with crankshaft angular position at a sampling rate to obtain sampled data; transforming the sampled data to an equivalent frequency domain spectrum, including frequency components having complex amplitudes at the engine cycle frequency and harmonics thereof; and applying an algorithm to the frequency components, which algorithm distinguishes between a true misfire and normal cyclic variability which characterizes the combustion process in each cylinder of the engine to thereby obtain a misfire signal, the step of applying the algorithm including the step of inputting the frequency components as input vectors to the pattern recognition system to identify the misfire.
Claim 3
Dependent Claim 35 words
The method of claim 1 wherein the frequency components have phases and wherein the magnitudes and phases of the frequency components are input to the pattern recognition system as input vectors to identify the misfire.
Claim 4
Dependent Claim 27 words
The method of claim 2 wherein the pattern recognition system includes a neural network having an input layer, at least one hidden layer, and an output layer.
Claim 5
Dependent Claim 45 words
The method of claim 2 further comprising the step of generating a load signal based on engine load, wherein the load signal and the magnitudes and phases of the frequency components are input to the pattern recognition system as input vectors to identify the misfire.
Claim 6
Dependent Claim 17 words
The method of claim 4 wherein the load signal is based on mass airflow to the engine.
Claim 7
Dependent Claim 21 words
The method of claim 4 wherein the engine has a manifold and wherein the load signal is based on manifold pressure.
Claim 8
Dependent Claim 51 words
The method of claim 4 further comprising the step of generating an RPM signal based on the speed of the engine wherein the RPM signal, the load signal and the magnitudes and phases of the frequency components are input to the pattern recognition system as input vectors to identify the misfire.
Claim 9
Dependent Claim 39 words
The method of claim 7 wherein the engine has a transmission attached thereto and wherein the method further comprises the step of providing a gear signal indicating a gear of the transmission wherein the algorithm utilizes the gear signal.
Claim 10
Independent Claim 158 words
A system for detecting a misfire of a reciprocating internal combustion engine including a plurality of reciprocating components having an engine cycle frequency, at least one cylinder and a crankshaft, the system comprising: means for generating an electrical signal as a function of crankshaft angular velocity, the electrical signal containing data; means for sampling the data synchronously with crankshaft angular position at a sampling rate to obtain sampled data; means for transforming the sampled data to an equivalent frequency domain spectrum, including frequency components having complex amplitudes at the engine cycle frequency; and means for applying an algorithm to the frequency components, which algorithm distinguishes between a true misfire and normal cyclic variability which characterizes the combustion process in each cylinder of the engine to thereby obtain a misfire signal, the means for applying the algorithm including a pattern recognition system for receiving the frequency components as input vectors and generating an output signal to identify the misfire.
Claim 11
Independent Claim 158 words
A system for detecting a misfire of a reciprocating internal combustion engine including a plurality of reciprocating components having an engine cycle frequency, at least one cylinder and a crankshaft, the system comprising: means for generating an electrical signal as a function of crankshaft angular velocity, the electrical signal containing data; means for sampling the data synchronously with crankshaft angular position at a sampling rate to obtain sampled data; means for transforming the sampled data to an equivalent frequency domain spectrum, including frequency components having complex amplitudes at the engine cycle frequency; and means for applying an algorithm to the frequency components, which algorithm distinguishes between a true misfire and normal cyclic variability which characterizes the combustion process in each cylinder of the engine to thereby obtain a misfire signal, the means for applying the algorithm including a pattern recognition system for receiving the frequency components as input vectors and generating an output signal to identify the misfire.
Claim 12
Dependent Claim 35 words
The system of claim 9 wherein the frequency components have phases and wherein the magnitudes and phases of the frequency components are input to the pattern recognition system as input vectors to identify the misfire.
Claim 13
Dependent Claim 27 words
The system of claim 10 wherein the pattern recognition system includes a neural network having an input layer, at least one hidden layer, and an output layer.
Claim 14
Dependent Claim 44 words
The system of claim 10 further comprising means for generating a load signal based on engine load, wherein the load signal and the magnitudes and phases of the frequency components are input to the pattern recognition system as input vectors to identify the misfire.
Claim 15
Dependent Claim 17 words
The system of claim 12 wherein the load signal is based on mass airflow to the engine.
Claim 16
Dependent Claim 21 words
The system of claim 12 wherein the engine has a manifold and wherein the load signal is based on manifold pressure.
Claim 17
Dependent Claim 50 words
The system of claim 12 further comprising means for generating an RPM signal based on the speed of the engine wherein the RPM signal, the load signal and the magnitudes and phases of the frequency components are input to the pattern recognition system as input vectors to identify the misfire.
Claim 18
Dependent Claim 38 words
The system of claim 15 wherein the engine has a transmission attached thereto and wherein the system further comprises means for providing a gear signal indicating a gear of the transmission wherein the algorithm utilizes the gear signal.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-02-26 1999-08-28 2000-02-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-02-26 2003-08-28 2004-02-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-02-26 2007-08-28 2008-02-27 $7700.00 Window Closed / Lapsed

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