Knocking Determination Device Waveform Segmentation
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Solution Overview
Problem
Existing knocking determination devices in internal combustion engines face errors in distinguishing between vibration waveforms caused by multiple noises or both noise and knock, leading to incorrect identification of knocking waveforms.
Innovation Solution
A knocking determination device that includes a detection unit, a knocking determination unit, an end determination unit, and a feature extraction unit, which identifies individual waveforms within a vibration waveform and determines their features to accurately match them with a knocking waveform, thereby preventing erroneous determinations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the knocking determination is performed based on whether or not a feature of a vibration waveform as a whole matches with a feature of a knocking waveform, then the knocking determination can be performed, but erroneous determination occurs when multiple noises or both noise and knock are generated during the predetermined period
Solution Approach 1:
The vibration waveform is divided into multiple individual waveform segments, each corresponding to a specific combustion cycle. The knocking determination unit then performs knocking determination on each individual waveform segment separately, rather than treating the entire vibration waveform as a single entity. This segmentation allows for accurate identification of knock events even when multiple noises are present, as each segment can be independently analyzed for its characteristic features.
2Reliability
If the vibration waveform including both noise and knock is analyzed as a whole, then the knocking determination can be performed, but the feature may be erroneously determined as a single knocking waveform
Solution Approach 1:
The vibration waveform is divided into multiple individual waveform segments, each corresponding to a specific combustion cycle. The knocking determination unit then performs knocking determination on each individual waveform segment separately, rather than treating the entire vibration waveform as a single entity. This segmentation allows for accurate identification of knock events even when multiple noises are present, as each segment can be independently analyzed for its characteristic features.
Solution Approach 2:
The knocking determination unit extracts and analyzes specific feature quantities from each individual waveform segment, such as peak value, rise time, and duration. By extracting these characteristic features and comparing them against predetermined thresholds or reference knock waveform features, the system can identify true knock events while filtering out noise components that do not exhibit the characteristic features of knock.
Data Source
Figure 1~2
Figure 3
Figure 4~4(c)
AI summary
A waveform of each predetermined series of vibrations included in a vibration waveform is referred to as an "individual waveform (Wo)". An end determination unit (34) determines an end of each individual waveform (Wo) and determines a boundary between the individual waveforms (Wo). A feature extraction unit (33) performs an extraction work of a feature (Ps, Pm, Pe) of each individual waveform (Wo) based on a recognition of the boundary. A knocking determination unit (35) determines whether or not the feature matches with a feature of a knocking waveform for each individual waveform (Wo) whose feature is extracted by the feature extraction unit (33). Then, it is determined that a knock exists on condition that any of the features in the individual waveform is determined as the feature of the knocking waveform.