Fuel Injection Correction via NOx Concentration and Induction Gas Ratio
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Solution Overview
Problem
Existing methods for detecting fuel injection deviations in internal combustion engines rely solely on exhaust oxygen sensors, which can lead to unnecessary fuel adjustments due to issues other than fueling errors, such as boost pressure errors, resulting in reduced engine power and increased fuel consumption.
Innovation Solution
A method that utilizes the correlation between the concentration of oxides of nitrogen (CNOx) in the exhaust system and the combusted mass of gas in the induction system to differentiate between fueling errors and boost errors, adjusting fuel injection parameters and exhaust gas recirculation to maintain optimal engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If exhaust oxygen sensor output is used to detect fueling errors, then fueling deviations can be detected, but unnecessary fuel adjustments occur due to boost pressure errors
Solution Approach 1:
The patent introduces NOx concentration as an intermediary measurement parameter between the exhaust oxygen sensor and the fuel injection control. Instead of directly using oxygen sensor output to adjust fuel injection, the system first measures NOx concentration, compares it with target values, and then determines whether fuel adjustments are actually needed. This intermediary step filters out false signals caused by boost pressure variations that don't affect NOx formation, thereby preventing unnecessary fuel adjustments while maintaining accurate fueling error detection.
2Manufacturing precision
If fuel injection is adjusted based on exhaust oxygen concentration, then fueling deviations are corrected, but engine power is reduced due to unnecessary adjustments
Solution Approach 1:
The patent implements a feedback control mechanism where NOx concentration measurements are continuously compared with target NOx values, and fuel injection adjustments are made only when actual NOx values deviate from targets beyond a threshold. This feedback loop ensures precise fuel injection correction when actually needed while avoiding power-reducing adjustments when deviations are within acceptable ranges or caused by non-fueling factors like boost pressure changes.
3Manufacturing precision
If fuel injection is adjusted based on exhaust oxygen concentration, then fueling deviations are corrected, but fuel consumption increases due to unnecessary adjustments
Solution Approach 1:
The patent uses NOx concentration as an intermediary indicator that more accurately reflects actual fuel combustion efficiency compared to exhaust oxygen concentration alone. By basing fuel injection adjustments on NOx measurements rather than oxygen measurements, the system avoids unnecessary fuel additions that would increase consumption. The NOx-based control logic determines true fueling deviations and applies corrections only when genuinely needed, thereby maintaining precise fuel injection without increasing overall fuel consumption.
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 allows for precise correction of fuel injection deviations, reducing unnecessary adjustments and maintaining efficient engine operation by accurately distinguishing between fueling and boost-related issues.
Implementation Method 1
via the exhaust gas recirculation system, a part of an exhaust gas mass flow produced by the internal combustion engine is branched out of the exhaust system, recirculated into an induction plenum chamber of the induction system and passed from there into the internal combustion engine
Implementation Method 2
an internal combustion engine of a motor vehicle having an induction system, an exhaust system, and an exhaust gas recirculation system
Data Source
AI summary
A method for adjusting an actual value of a quantity of fuel injected into an internal combustion engine of a motor vehicle to a target value is provided, wherein a deviation of the actual quantity of fuel injected from the target value is determined based on a ratio of the component of the combusted quantity of gas in the induction system to the concentration of oxides of nitrogen in the exhaust system and the injected quantity of fuel is readjusted according to the deviation. Furthermore, an arrangement for carrying out the method is provided.