Air Flow Measurement Device Pulsation Error Correction
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Solution Overview
Problem
Existing air flow measurement devices for internal combustion engines face challenges in accurately calculating pulsation amplitude ratios and correcting pulsation errors due to the inherent instability of minimum flow rate measurements, leading to reduced reproducibility and accuracy.
Innovation Solution
An air flow measurement device that includes an average air amount calculation unit, pulsation amplitude calculation unit, pulsation error prediction unit, and pulsation error correction unit, which calculates the pulsation maximum value from the output value of a sensing unit to reduce the influence of unstable minimum flow rate measurements and predict and correct pulsation errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If minimum flow rate measurements are used to calculate pulsation amplitude ratio, then the measurement can be performed, but the reproducibility and accuracy are reduced due to instability
Solution Approach 1:
The patent extracts and eliminates the unstable minimum flow rate measurements from the pulsation amplitude ratio calculation. Instead of using both maximum and minimum flow rates, the invention only utilizes maximum flow rate measurements, thereby removing the source of instability and improving both accuracy and reproducibility of the pulsation amplitude ratio measurement.
2Measurement precision
If pulsation error correction is applied using traditional methods, then correction can be performed, but the correction parameters remain unstable due to minimum flow rate influence
Solution Approach 1:
The patent removes the influence of unstable minimum flow rate measurements from the correction parameter calculations. By calculating pulsation amplitude ratio exclusively from maximum flow rate measurements, the correction parameters become more stable and reliable, leading to improved air flow rate calculation accuracy.
Solution Approach 2:
The patent implements a feedback mechanism where the pulsation amplitude ratio, calculated from stable maximum flow rate measurements, is used to determine correction parameters that are then applied to improve the overall air flow rate measurement accuracy. This feedback loop ensures that unstable minimum flow rate measurements do not propagate errors through the correction process.
Data Source
AI summary
An air flow measurement device that measures an air flow rate based on an output value of a sensing unit attached in an environment in which air flows, the air flow measurement device is provided. The air flow measurement device may calculate an average air amount, which is an average value of the air flow rate, from the output value. The air flow measurement device may calculate a pulsation maximum value, which is a maximum value of the air flow rate, from the output value.