Modified trimmed mean filtering for misfire detection
AssigneeMotorola, Inc.
InventorsMarvin L. Lynch, Michael A. McClish, Margaret A.. Selfe, Gregory Steinl
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Abstract
A modified trimmed mean filtering method and apparatus for a misfire detection includes acquiring a time-continuous series of acceleration data samples (601) representative of acceleration behavior of a reciprocating engine. And, providing a filtered acceleration data sample (607) dependent on an average acceleration magnitude of a portion of the acceleration data samples bounded within a range of amplitudes and, preferably, a time-centered acceleration data sample (606) of the fixed length time-continuous series of acceleration data samples. A misfire condition can be indicated (409) dependent on a magnitude of the filtered acceleration data sample.
Claims16
A modified trimmed mean filtering method for a misfire detection system for a reciprocating engine comprising the steps of:
- acquiring a fixed length time-continuous series of acceleration data samples representative of acceleration behavior of the reciprocating engine;
- providing a filtered acceleration data sample dependent on an average acceleration magnitude of a portion of the acceleration data samples bounded within a range of amplitudes and a singular acceleration data sample of the fixed length time-continuous series of acceleration data samples;
- measuring engine speed;
- wherein a magnitude of the range of amplitudes is determined dependent on the engine speed;
- and
- indicating a misfire condition dependent on a magnitude of the filtered acceleration data sample.
A modified trimmed mean filtering method for a misfire detection system for a reciprocating engine comprising the steps of:
- acquiring a fixed length time-continuous series of acceleration data samples representative of acceleration behavior of the reciprocating engine;
- determining a median acceleration data sample that has a magnitude median within the fixed length time-continuous series of acceleration data samples;
- measuring engine speed determining a range variable dependent on the engine speed;
- selecting a plurality of acceleration data samples from the fixed length time-continuous series of acceleration data samples that have magnitudes bounded within a range of median acceleration data sample minus the range variable and the median acceleration data sample plus the range variable;
- providing an average acceleration magnitude dependent on an average magnitude of the selected plurality of acceleration data samples;
- determining a filtered acceleration sample dependent on the average acceleration magnitude and a time-centered acceleration data sample of the fixed length time-continuous series of acceleration data samples;
- and
- indicating a misfire condition dependent on a magnitude of the filtered acceleration data sample.
A modified trimmed mean filtering apparatus for a misfire detection system for a reciprocating engine comprises:
- acceleration measurement means for acquiring a fixed length time-continuous series of acceleration data samples representative of acceleration behavior of the reciprocating engine;
- means for measuring an operating condition of the reciprocating engine;
- means for determining a median acceleration data sample that has a magnitude median within the fixed length time-continuous series of acceleration data samples;
- means for determining a range variable dependent on the operating condition of the reciprocating engine;
- means for selecting a plurality of acceleration data samples from the fixed length time-continuous series of acceleration data samples that have magnitudes bounded within a range of median acceleration data sample minus the range variable and the median acceleration data sample plus the range variable;
- means for providing an average acceleration magnitude dependent on an average magnitude of the selected plurality of acceleration data samples;
- means for determining a filtered acceleration data sample dependent on the average acceleration magnitude and a time-centered acceleration data sample of the fixed length time-continuous series of acceleration data samples;
- and
- a device for indicating a misfire condition dependent on a magnitude of the filtered acceleration data sample.
Dependencies are inferred from the claim text.