Fuel Injection Compensation Using Cylinder-Specific Oxygen Sensor Feedback
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Solution Overview
Problem
Current fuel injection control technologies do not account for torque deviations between individual cylinders in an engine, leading to reduced fuel efficiency and increased exhaust gas emissions, as well as compromised engine durability.
Innovation Solution
An apparatus and method that utilize an oxygen sensor to measure output voltage during the exhaust stroke of each cylinder, applying high-pass filtering to compensate for fuel injection quantities based on calculated offsets, thereby reducing torque deviations by adjusting fuel injection in each cylinder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional fuel injection control based on oxygen sensor feedback is used, then the overall air-fuel ratio can be maintained, but torque deviation between individual cylinders cannot be corrected leading to cylinder imbalance
Solution Approach 1:
The patent segments the exhaust stream into individual cylinder contributions by using a rotating valve to direct exhaust from specific cylinders to the oxygen sensor. This allows the control system to measure oxygen concentration from each cylinder separately and apply individualized fuel injection corrections, thereby resolving the torque imbalance issue that conventional aggregate-based control cannot address
Solution Approach 2:
The patent implements a feedback control mechanism where the oxygen sensor measures the air-fuel ratio of exhaust from individual cylinders, and the ECU uses this feedback information to dynamically adjust the fuel injection quantity for each cylinder. This closed-loop feedback system continuously corrects deviations in real-time, ensuring optimal torque balance and combustion efficiency
2Productivity
If individual cylinder torque compensation is implemented, then fuel efficiency and engine durability improve, but system complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The patent makes the existing oxygen sensor serve multiple functions: it measures both the overall exhaust air-fuel ratio and, when combined with the rotating valve, the individual cylinder exhaust composition. This multi-functional use of existing components achieves individual cylinder compensation without requiring separate sensors for each cylinder, thereby limiting the increase in system complexity
Solution Approach 2:
The rotating valve acts as an intermediary device that enables the oxygen sensor to selectively measure exhaust from individual cylinders. This mediator component allows the system to obtain detailed cylinder-specific information using relatively simple means, achieving complex measurement goals without proportionally increasing system complexity
3Loss of time
If oxygen sensor measures exhaust during all strokes, then continuous monitoring is achieved, but measurement accuracy decreases due to interference from non-exhaust gases
Solution Approach 1:
The patent employs periodic sampling of exhaust gases from each cylinder through the rotating valve, which sequentially directs exhaust from different cylinders to the oxygen sensor at regular intervals. This periodic action ensures that measurements are taken during the exhaust stroke when oxygen concentration information is most reliable, maintaining measurement precision while achieving comprehensive monitoring coverage
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 improves fuel efficiency, reduces exhaust gas emissions, and enhances engine durability by minimizing torque deviations between cylinders through precise fuel injection compensation.
Implementation Method 1
the oxygen sensor may use zirconia generating electromotive force when oxygen quantity on both zirconia surfaces of the oxygen sensor becomes different
Data Source
AI summary
Provided are an apparatus and a method for compensating for a fuel injection quantity in an engine of a vehicle. The apparatus for compensating for a fuel injection quantity may include: an information collector collecting status information of the vehicle; an oxygen sensor outputting a voltage corresponding to a concentration of oxygen in exhaust gases; a high pass filter (HPF) filtering the output voltage of the oxygen sensor; and a controller generating a reference value on the basis of the status information of the vehicle. In particular, the controller calculates an offset using the reference value and a signal obtained by high-pass filtering the output voltage, and compensates for a fuel injection quantity in each individual cylinder of the engine of the vehicle on the basis of the offset.