Methods and apparatus for detecting misfires
First Claim
1. A method of identifying one or more misfires occurring in an internal combustion engine, the method including the steps of:
- a. running the engine;
b. measuring the pressure pulses from the exhaust of the engine;
c. generating a waveform from the measured pressure pulses;
d. dividing the waveform into segments, one for each cylinder of the engine, wherein each segment represents a pressure pulse;
e. associating each waveform segment with the cylinder which generated the pressure pulse; and
f. examining each waveform segment for features which indicate a misfire.
4 Assignments
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Accused Products
Abstract
Identifying fires by: measuring pressure pulses from the exhaust; generating a waveform from the measured pressure pulses; dividing the waveform into segments, one for each engine cylinder; associating each segment with the cylinder which generated the pulse; and examining each segment for features which indicate a misfire. The method further includes: generating a trigger signal; associating the trigger signal with ignition in a cylinder; measuring the time between this signal and the next trigger signal; dividing the time between these trigger signals into cylinder boxes, one for each cylinder; and shifting each of the boxes relative to the associated segment such that the peak and a portion of the rising edge and/or the falling edge falls within the box. For each box the peak, rising edge and falling edge is compared with threshold values. Each box in which at least two of the thresholds are exceeded is flagged.
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Citations
15 Claims
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1. A method of identifying one or more misfires occurring in an internal combustion engine, the method including the steps of:
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a. running the engine; b. measuring the pressure pulses from the exhaust of the engine; c. generating a waveform from the measured pressure pulses; d. dividing the waveform into segments, one for each cylinder of the engine, wherein each segment represents a pressure pulse; e. associating each waveform segment with the cylinder which generated the pressure pulse; and f. examining each waveform segment for features which indicate a misfire. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification