Fuel Injector Transfer Function Learning via Quiet Zone Pressure Sampling
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Solution Overview
Problem
Existing fuel injection systems in engines with multiple cylinders and injectors face challenges in accurately balancing fuel delivery due to variability in injector performance over time, leading to reduced fuel economy, increased emissions, and torque variation, as current methods for correcting injector errors are complex and time-consuming.
Innovation Solution
A method that adjusts fuel injection parameters based on a fuel rail pressure drop sensed during a specific diagnostic period, allowing for the learning and application of a common injector transfer function shape across all direct injectors, reducing the number of injections needed to determine this shape and enhancing the speed of injector fueling correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional methods use average inter-injection pressure to estimate fuel rail pressure drop for each injector, then injector fueling errors can be corrected, but the process becomes complex and time-consuming
Solution Approach 1:
The patent segments the pressure measurement process by identifying and discarding noisy pressure samples that occur during the ballistic and transition regions of injector operation. Only pressure samples from the quiet zone (steady-state region) are used for calculating average inter-injection pressure, thereby simplifying the correction process while maintaining accuracy.
Solution Approach 2:
The patent applies preliminary action by pre-identifying the quiet zone window before performing pressure measurements. The controller is configured to selectively discard noisy samples based on predetermined timing windows, allowing the system to prepare the measurement conditions in advance and avoid complex real-time filtering during the correction process.
2Measurement precision
If traditional methods discard noisy pressure samples and average only quiet zone samples, then measurement accuracy improves, but the learning time for injector corrections is prolonged
Solution Approach 1:
The patent applies dynamics by adaptively adjusting the measurement strategy based on operating conditions. The controller dynamically identifies the quiet zone window and selectively averages pressure samples only from this region, optimizing the balance between measurement accuracy and learning speed for each specific operating condition.
Solution Approach 2:
The patent changes the measurement parameters by transitioning from using all pressure samples to using only samples within the identified quiet zone window. This parameter change allows the system to maintain high measurement accuracy while reducing the number of samples that need to be processed, thereby reducing learning time.
3Power
If engines operate with multiple fuel injectors to handle higher cylinder counts, then engine performance improves, but injector variability and fueling inconsistency increase
Solution Approach 1:
The patent applies universality by developing a common injector transfer function shape that can be applied to all direct injectors in the engine, regardless of cylinder count. This universal approach allows the system to maintain consistent fueling accuracy across multiple injectors by using a single learned shape for all injector corrections.
Solution Approach 2:
The patent implements feedback by continuously monitoring fuel rail pressure during injector operation and using this information to update and refine the injector transfer function shape. The system uses actual pressure measurements from multiple injectors to feedback-correct the common shape, thereby improving fueling consistency across all injectors.
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 enables quicker learning and correction of injector fueling errors, improving engine efficiency, reducing emissions, and enhancing fuel economy by applying a consistent fuel injection pattern across all injectors, thus addressing the variability issues in existing systems.
Implementation Method 1
determining a fuel injection amount for an injector based on a difference in fuel rail pressure
Data Source
AI summary
Methods and systems are provided for balancing a plurality of fuel injectors. In one example, a method includes determining a fuel injector error shape and applying a fueling correction to all injectors based on the fuel injector error shape.