Engine Air Flow Sensor Correction via Multi-Frequency Pulsation Analysis
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Solution Overview
Problem
Conventional internal combustion engine control devices correct air flow rates based on pulsation frequency and amplitude ratio, but errors still occur between corrected and actual air flow rates, especially under varying operation conditions.
Innovation Solution
An internal combustion engine control device with an arithmetic unit that derives a fundamental frequency from the engine's rotational speed, extracts radio frequencies from the pulsation waveform, calculates their amplitudes, and uses these to derive correction amounts for more accurate air flow rate calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If correction is performed based only on pulsation frequency and amplitude ratio, then the correction process is simple, but measurement precision of air flow rate deteriorates under varying operation conditions
Solution Approach 1:
The pulsation waveform correction process is segmented into multiple frequency components. Instead of treating pulsation as a single frequency phenomenon, the invention extracts and corrects for fundamental frequency and higher-order radio frequencies separately. This segmentation allows each frequency component to be corrected individually, improving overall measurement precision while keeping the correction process systematically organized
Solution Approach 2:
The invention adds a frequency dimension to the correction process by analyzing pulsation waveforms across multiple frequency bands. By transforming the correction approach from single-parameter (amplitude ratio) to multi-frequency spectrum analysis, the system achieves higher measurement precision without proportionally increasing device complexity
2Measurement precision
If multi-frequency analysis is performed to improve correction accuracy, then measurement precision of air flow rate improves, but device complexity increases
Solution Approach 1:
The correction system dynamically adapts to different engine operating conditions by continuously analyzing the pulsation waveform spectrum. The arithmetic device identifies which frequency components are present and adjusts the correction process accordingly, rather than always performing full multi-frequency analysis. This dynamic approach maintains high measurement precision while reducing unnecessary computational complexity
Solution Approach 2:
The system uses feedback from the pulsation waveform analysis to determine the appropriate correction level. By monitoring the engine's operational state through the pulsation characteristics, the arithmetic device can adjust the correction process in real-time, applying more sophisticated multi-frequency correction only when needed, thus balancing precision with complexity
Data Source
AI summary
Provided is an internal combustion engine control device capable of more appropriately correcting an output value of a flow rate sensor that measures a flow rate of air flowing through an intake flow path of an internal combustion engine, and further reducing an error between a corrected air flow rate and an actual air flow rate as compared to a conventional device. For this purpose, the internal combustion engine control device of the present invention includes an arithmetic device 100 including a fundamental frequency derivation unit 104 that derives a fundamental frequency, a flow rate amplitude calculation unit 107 that extracts a radio frequency of a plurality of frequencies equal to or higher than the fundamental frequency from a pulsation waveform based on the output value of the flow rate sensor as a flow rate radio frequency and calculates an amplitude of the flow rate radio frequency for each frequency, a correction amount derivation unit 108 that derives a correction amount based on the amplitude of the flow rate radio frequency for each frequency, and a flow rate calculation unit 109 that calculates a flow rate of air by using the output value of the flow rate sensor and the correction amount.