Engine All-Cylinder Misfire Detection with Pulsation Spectrum Analysis
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Solution Overview
Problem
Existing misfire detecting devices for internal combustion engines take time to detect all-cylinder misfires, particularly in engines with a large number of cylinders, leading to increased non-combustion gas generation.
Innovation Solution
An internal combustion engine misfire detecting device that frequency-analyzes operation parameter data to identify pulsating components and difference parameters, using threshold values to quickly determine all-cylinder misfires without individual cylinder assessments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If individual cylinder misfire detection is performed, then misfire detection accuracy is improved, but detection time increases
Solution Approach 1:
The patent combines the detection of multiple cylinders into a single integrated detection process. Instead of individually analyzing each cylinder's operation, the system merges the operational parameters of all cylinders and analyzes them as a collective unit, thereby maintaining detection accuracy while significantly reducing the time required to identify all-cylinder misfires
Solution Approach 2:
The patent segments the detection process into two distinct stages: first identifying whether a misfire occurred in any cylinder, then determining if it was an all-cylinder misfire. This segmentation allows the system to quickly rule out partial misfires and focus computational resources only when necessary, reducing overall detection time while maintaining accuracy
2Reliability
If individual cylinder assessment is performed, then misfire detection reliability is improved, but device complexity increases
Solution Approach 1:
The patent employs a universal detection approach where a single integrated analysis mechanism serves multiple functions: it detects both partial misfires and all-cylinder misfires, and can identify the specific type of misfire occurrence. This multi-functional approach maintains high reliability while reducing system complexity compared to separate detection mechanisms for different misfire types
3Object-generated harmful factors
If all-cylinder misfire detection is delayed, then non-combustion gas generation increases, but detection speed decreases
Solution Approach 1:
The patent performs preliminary analysis of operational parameters continuously during engine operation, preparing detection criteria and threshold values in advance. When a misfire condition occurs, the system can immediately compare current parameters against pre-established criteria, enabling rapid detection of all-cylinder misfires before significant non-combustion gas accumulation occurs
Data Source
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AI summary
This misfire detecting device for an internal combustion engine having a plurality of cylinders, for detecting a misfire of the internal combustion engine, is provided with: a pulsation component acquiring unit for performing a frequency analysis of operating parameter data indicating a change over time in an operating parameter correlated with an overall operating state of the plurality of cylinders, and for acquiring a pulsation component spectrum, which is a frequency spectrum of pulsations of the internal combustion engine; a difference parameter acquiring unit for acquiring a difference parameter correlated with a degree of difference between the operations of each of the plurality of cylinders; and all-cylinder misfire determining unit for determining that an all-cylinder misfire has occurred in the internal combustion engine if the pulsation component spectrum acquired by the pulsation component acquiring unit falls below a first threshold and the difference parameter acquired by the difference parameter acquiring unit 12 falls below a second threshold.