Knocking Detection via Multi-Band Vibration Filtering
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Solution Overview
Problem
Existing knocking determination devices for internal combustion engines face challenges in accurately detecting vibrations due to varying frequency components and noise interference, leading to reduced accuracy in determining whether knocking occurs.
Innovation Solution
A knocking determination device that detects vibrations across multiple frequency bands with identical bandwidths, using a detecting unit, extracting unit, and determining unit to identify vibrations specific to knocking, and compares detected waveforms with stored models to determine knocking occurrence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency components are detected across multiple frequency bands to capture knocking vibrations, then the ability to detect knocking is improved, but noise components from other frequency bands increase and deteriorate detection accuracy
Solution Approach 1:
The patent divides the frequency spectrum into multiple frequency bands (first frequency band, second frequency band, third frequency band) and processes each band separately. This segmentation allows the system to capture knocking vibrations across different frequency ranges while maintaining the ability to filter noise in each specific band, resolving the contradiction between comprehensive detection and precision measurement.
Solution Approach 2:
Each frequency band is processed with specific local characteristics - the first frequency band captures high-frequency knocking components, the second band captures medium-frequency components, and the third band captures low-frequency components. This local quality approach allows optimized detection parameters for each frequency range, improving overall detection reliability while maintaining measurement precision through band-specific processing.
2Adaptability or versatility
If the bandwidth of frequency bands is increased to detect more frequency components, then detection coverage is improved, but noise components increase and accuracy deteriorates
Solution Approach 1:
The patent segments the overall frequency spectrum into three distinct frequency bands with specific bandwidths. This segmentation provides comprehensive frequency coverage while keeping each individual band's bandwidth optimized to minimize noise inclusion, thus maintaining measurement precision across the entire detection range.
Solution Approach 2:
The patent uses a balanced approach where each frequency band has a specific bandwidth that is neither too narrow (missing important components) nor too wide (including excessive noise). The first frequency band has bandwidth of 2-10 kHz, the second has 10-20 kHz, and the third has 20-30 kHz, providing partial coverage optimized for each band's specific noise characteristics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of knocking determination by filtering out noise and consistently identifying vibrations associated with knocking, allowing for precise control of the engine's operation state.
Implementation Method 1
a detecting unit detecting vibrations of an internal combustion engine
Data Source
AI summary
An engine ECU 200 includes a bandpass filter (1), a bandpass filter (2), and a bandpass filter (3). The bandpass filter (1) extracts only vibrations at a first frequency band A from the vibrations detected by a knock sensor. The bandpass filter (2) extracts only vibrations at a second frequency band B from the vibrations detected by the knock sensor. The bandpass filter (3) extracts only vibrations at a third frequency band C from the vibrations detected by the knock sensor. The first to third frequency bands A-C are identical in bandwidth. The engine ECU calculates a peak value in magnitude of vibrations in a synthesized waveform of these frequency bands, and determines whether knocking occurred or not based on the peak value.