Alcohol Estimation via Segmented Air-Fuel Correction
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Solution Overview
Problem
Existing methods for estimating the alcohol component in composite fuel for Flexible Fuel Vehicles (FFVs) suffer from insufficient accuracy due to the lack of consideration for engine individual differences and variations over time, and the use of expensive sensors for direct detection.
Innovation Solution
An estimation apparatus comprising an exhaust air-fuel ratio detection unit, feedback correction value setting, learning control, estimation condition determination, and computation units to estimate the alcohol component amount based on air-fuel ratio corrections and change rates, without the need for expensive sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If learning control is continuously executed to compensate for engine individual differences, then the adaptability to engine variations is improved, but the measurement precision of alcohol concentration estimation deteriorates due to reflected learning corrections in the estimation algorithm
Solution Approach 1:
The patent segments the air-fuel ratio correction into two independent parts: learning correction (for engine individual differences) and feedback correction (for alcohol concentration estimation). By separating these correction components, the system can independently manage each function without interference, resolving the contradiction between adaptability and measurement precision.
Solution Approach 2:
The patent introduces an intermediary mechanism by using the learning correction value as a reference baseline and applying feedback correction relative to this baseline. This intermediary approach allows the system to account for engine variations while maintaining accurate alcohol concentration measurements by comparing changes against the learned baseline rather than absolute values.
2Measurement precision
If expensive fuel property sensors are installed in the fuel tank for direct detection, then the measurement precision of fuel property is improved, but the manufacturing cost increases
Solution Approach 1:
The patent enables the existing air-fuel ratio sensor and engine control system to perform the additional function of alcohol concentration estimation by processing existing sensor data through a dedicated estimation algorithm. This self-service approach eliminates the need for separate expensive fuel property sensors while maintaining measurement precision.
Solution Approach 2:
The patent makes the existing air-fuel ratio sensing system multi-functional by enabling it to serve both its original purpose (engine control) and the additional purpose of alcohol concentration estimation. This universality eliminates the need for dedicated expensive sensors, reducing manufacturing costs while maintaining measurement accuracy.
3Reliability
If air-fuel ratio learning correction is used to compensate for engine variations, then the reliability of fuel injection control is improved, but the measurement precision of alcohol concentration estimation deteriorates due to the reflection of learning effects in the estimation
Solution Approach 1:
The patent segments the correction mechanism into learning correction (for reliability) and feedback correction (for measurement precision). By calculating feedback correction as the difference from the learned baseline rather than from absolute values, the system maintains reliable fuel injection control while achieving accurate alcohol concentration estimation.
Solution Approach 2:
The patent implements a feedback mechanism that uses the learning correction value as a reference baseline. The feedback correction is calculated based on the deviation from this baseline, allowing the system to maintain reliable control while accurately estimating alcohol concentration by measuring changes relative to the learned state rather than absolute values.
Data Source
AI summary
An estimation apparatus includes: a learning prohibition unit, configured to prohibit a learning unit from executing a learning control and retain a learning value, which is set just before prohibiting, as a fixed learning value which is a fixed value, when the fuel component amount estimation condition is satisfied; an air-fuel ratio correction amount computation unit, configured to compute a correction amount of the air-fuel ratio based on the feedback correction value and the fixed learning value, when the fuel component amount estimation condition is satisfied; an injection correction value change rate computation unit, configured to compute a change rate of the correction amount; an alcohol component correction value computation unit, configured to compute an alcohol component correction value based on the change rate; and an alcohol component amount estimation unit, configured to estimate an alcohol component amount in fuel based on the alcohol component correction value.